PBPath Journal Watch Articles

Welcome to the PBPath Journal Watch!

This bi-monthly journal watch features exciting recently published pancreas and biliary pathology articles that will provide up to date medical knowledge in our field. These articles will be showcased in several convenient categories, including surgical pathology, cytopathology, molecular pathology, pancreas, gallbladder, bile ducts, and ampulla among others. The articles in each category are in no particular order. See the list of journals we search regularly here. Previous months’ issues may be found in our archive and you may see drafts of the upcoming issue here.

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- Prevalence of histological features resembling autoimmune pancreatitis in neoplastic pancreas resections

Histopathology 2020 Jul;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32608526

INTRODUCTION: Type 1 and type 2 autoimmune pancreatitis (AIP) can mimic pancreatic neoplasia. Due to the small quantity of tissue in mass-targeted pancreas biopsies, inflammatory features may raise the differential of AIP. However, the frequency of AIP-like histology in neoplastic pancreas is not well characterized. Therefore, the specificity of inflammatory lesions on biopsy with respect to the diagnosis of AIP is uncertain. MATERIALS AND METHODS: Neoplastic pancreas resections performed at our institution between 2008 to 2019 were retrospectively reviewed. Features of AIP type 1 and 2 were assessed in the non-neoplastic areas. If features of IgG4-associated AIP were seen, IgG4 immunohistochemistry was performed. RESULTS: We identified 163 neoplastic pancreas resections. Of these, 34 had one or more types of inflammatory lesions in non-neoplastic pancreatic tissue. Dense lymphoplasmacytic inflammation mimicking type 1 AIP was found in 6 cases with mild to moderately increased IgG4 positive plasma cells. Neutrophilic infiltrates in small intralobular ducts were found in 20 cases. Mild extra-lobular ductitis or duct microabscess was found in 10 specimens. Marked neutrophilic duct destruction that resembled granulocytic epithelial lesions was found in 12 cases. Some cases showed multiple features. CONCLUSION: Approximately 20% of neoplastic pancreas resections showed focal areas that could raise the differential of AIP. More cases showed neutrophilic predominant inflammation, as seen in type 2 autoimmune pancreatitis, compared to dense lymphoplasmacytic infiltrates seen in type 1 AIP. Pathologists must be cautious when making a diagnosis of AIP on biopsy tissue based on histological findings alone.

doi: https://doi.org/10.1111/his.14197

- Circulating tumor DNA is prognostic and potentially predictive of eryaspase efficacy in second-line in patients with advanced pancreatic adenocarcinoma

Clinical cancer research : an official journal of the American Association for Cancer Research 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32605910

BACKGROUND: Eryaspase is composed of L-asparaginase encapsulated in erythrocytes and has demonstrated significant efficacy in a randomized phase 2 trial. We assessed the prognostic and predictive value of circulating tumor DNA (ctDNA) in patients plasma included in this trial. PATIENTS AND METHODS: Samples prospectively collected pre-treatment were centrally analyzed by next-generation sequencing. Prognostic values of baseline ctDNA and ctDNA early changes between day 0 and 28 were assessed in both arms combined on objective response rate (ORR), progression free survival (PFS) and overall survival (OS); three groups were defined: negative ctDNA (Neg), ctDNA responders (Resp) and ctDNA non-responders (NResp). Predictive value of ctDNA for eryaspase efficacy was investigated. RESULTS: CtDNA was positive at baseline in 77 patients out of the 113 tested patients (68%). Detectable ctDNA was an independent negative prognostic factor for OS (4.6 vs 8.8 months; p=0.0025) and PFS (1.6 vs 3.3 months; p=0.00043). Early change in ctDNA levels was correlated with ORR (20 %, 26%, 0%; p<0.04), PFS (3.7, 3.4, 1.6 months; p<0.0001) and OS (11.7, 6.5, 4.3 months; p<0.0001) according to the three defined groups (Neg, Res, NResp, respectively). In patients with ctDNA detectable at baseline, eryaspase was associated with better PFS (HR=0.53; 95% CI: 0.3-0.94) and OS (HR=0.52; 95% CI: 0.29-0.91). CONCLUSIONS: We confirm from a prospective randomized trial that 1/ the presence of ctDNA at baseline is a major prognostic factor, 2/ the early change of ctDNA correlates with treatment outcome and 3/ the ctDNA could be a predictive biomarker of eryaspase efficacy.

doi: https://doi.org/10.1158/1078-0432.CCR-20-0950

- A Morphologic and Immunohistochemical Comparison of Nuclear ��-Catenin Expressing Testicular Sertoli Cell Tumors and Pancreatic Solid Pseudopapillary Neoplasms Supporting Their Continued Separate Classification

The American journal of surgical pathology 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32604170

Some recent reports suggested that many Sertoli cell tumors, not otherwise specified (SCTs-NOS) of the testis were analogs of the solid pseudopapillary neoplasm (SPN) of the pancreas. One of the most relied on pieces of information for this assertion was the shared occurrence in both neoplasms of exon 3 mutations of the CTNNB1 gene, which was reflected by nuclear β-catenin expression. We, therefore, compared the morphologic and immunohistochemical features of 18 SCTs-NOS with strong, diffuse nuclear β-catenin expression with 16 SPNs that also showed such positivity. Although there were clear similarities in the light microscopic features of these neoplasms, there were also significant differences that included, in SCT-NOS and SPN, respectively: hollow tubules (53% vs. 0%), sheet-like growth (44% vs. 94%), circumscription (79% vs. 25%), corded or trabecular patterns (81% vs. 31%), formation of papillae or pseudopapillae (24% vs. 69%), growth in nests or clusters (94% vs. 50%), perivascular pseudorosettes (13% vs. 56%), and rhabdoid cytology (6% vs. 50%). Commonly shared morphologic features included signet-ring cells, pale or foamy cytoplasm, myxoid stroma, cyst formation, perivascular hyalinization, and globular or band-like basement membrane deposits. On immunohistochemical study, sex cord markers were frequently positive in SCTs-NOS (steroidogenic factor-1-94%; FOXL2-87%; SOX9-69%; calretinin-60%; Wilms tumor-1-38%; inhibin-29%) whereas all of these markers were negative in the SPNs. We conclude that even though SCT-NOS and SPN share some morphologic features and nuclear immunoreactivity for β-catenin, there remain differences, both morphologically and immunohistochemically, between these neoplasms to the degree that SCT-NOS should not be equated with pancreatic SPN.

doi: https://doi.org/10.1097/PAS.0000000000001527

- Landscape of RAS Variations in 17,993 Pan-cancer Patients Identified by Next-generation Sequencing

Pathology oncology research : POR 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32602003

RAS family genes (HRAS, KRAS and NRAS) were frequently observed in several tumors. The expression of constitutively active RAS proteins mediated by RAS variations promote the development of tumors. KRAS is an important prognostic and drug resistance biomarker. It would also be a promising drug target. Several trials which evaluating the efficacy of RAS G12C inhibitor in solid tumors are initiated. Herein, we analyzed the alterations status of KRAS/NRAS/HRAS across diverse solid tumors. The sing nucleotide variants (SNV) and copy number variants (CNV) data of 17993 Chinese patients from 22 types of cancer were obtained in our database. Genomic profiling of DNA was performed through a next-generation sequencing on tissue. Only the pathogenic mutations and likely pathogenic mutations in clinical significance were rolled into our analysis. Among 17993 pan-cancer patients, the total RAS variants frequency was 22.58%. KRAS was the most frequently altered, followed by NRAS and HRAS. For the SNV, KRAS were most commonly found in pancreas cancer, intestine cancer and colorectal cancer. Further analysis among KRAS SNV patients showed that the mutation frequency of KRAS G12C, G12D, G12R, and G12V was 1.81%, 6.81%, 0.69% and 4.25%, respectively. A total of 21 in 22 types of solid tumors had KRAS G12C/D/R/V pathogenic or likely pathogenic mutation, which occurred most frequently in colorectal cancer, pancreas cancer and lung cancer. Our results suggested that a variety of solid tumors may harbor KRAS G12C/D/R/V mutation. These patients may benefit from KRAS inhibitors.

doi: https://doi.org/10.1007/s12253-020-00845-9

- Multiclass cancer classification in fresh frozen and formalin-fixed paraffin-embedded tissue by DigiWest multiplex protein analysis

Laboratory investigation; a journal of technical methods and pathology 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32601356

Histomorphology and immunohistochemistry are the most common ways of cancer classification in routine cancer diagnostics, but often reach their limits in determining the organ origin in metastasis. These cancers of unknown primary, which are mostly adenocarcinomas or squamous cell carcinomas, therefore require more sophisticated methodologies of classification. Here, we report a multiplex protein profiling-based approach for the classification of fresh frozen and formalin-fixed paraffin-embedded (FFPE) cancer tissue samples using the digital western blot technique DigiWest. A DigiWest-compatible FFPE extraction protocol was developed, and a total of 634 antibodies were tested in an initial set of 16 FFPE samples covering tumors from different origins. Of the 303 detected antibodies, 102 yielded significant correlation of signals in 25 pairs of fresh frozen and FFPE primary tumor samples, including head and neck squamous cell carcinomas (HNSC), lung squamous cell carcinomas (LUSC), lung adenocarcinomas (LUAD), colorectal adenocarcinomas (COAD), and pancreatic adenocarcinomas (PAAD). For this signature of 102 analytes (covering 88 total proteins and 14 phosphoproteins), a support vector machine (SVM) algorithm was developed. This allowed for the classification of the tissue of origin for all five tumor types studied here with high overall accuracies in both fresh frozen (90.4%) and FFPE (77.6%) samples. In addition, the SVM classifier reached an overall accuracy of 88% in an independent validation cohort of 25 FFPE tumor samples. Our results indicate that DigiWest-based protein profiling represents a valuable method for cancer classification, yielding conclusive and decisive data not only from fresh frozen specimens but also FFPE samples, thus making this approach attractive for routine clinical applications.

doi: https://doi.org/10.1038/s41374-020-0455-y

- Duration-dependent effects induced by titanium dioxide nanoparticles on pancreas of adult male albino rats (histological and biochemical study)

Ultrastructural pathology 2020 Jun;():1-17

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32600082

Titanium dioxide nanoparticles (TiO2NPs) have been widely used in numerous applications and enter the human body through different routes. This study aimed to investigate the effect of intraperitoneal TiO2NPs on the histological and biochemical structure of rat pancreas. Fifty adult male albino rats were divided into four groups. Group I (control) was equally divided into two subgroups. Groups II, III, and IV: rats received intraperitoneal TiO2NPs for 7, 14, and 45 days, respectively. Blood samples were taken for the estimation of blood glucose, serum insulin, serum α-amylase, and lipase activity levels. Sections of the pancreas were processed for light, electron microscope examination, and immunohistochemical detection of insulin protein. Other parts were exposed to Real-Time Polymerase Chain Reaction for Bax, Bcl-2, SOD, and GST mRNA gene expression. Results showed pancreatic tissue damage, including acinar and islet cells, which became worse with increased duration of exposure to TiO2NPs. Decreased immune expression of the insulin protein together with decreased serum insulin and increased blood glucose levels indicated the alteration of β cells. Decreased serum α-amylase and lipase activities indicated alteration of acinar cells. Increased Bax and decreased Bcl-2 mRNA expression levels showed the apoptotic effect of TiO2NPs caused by oxidative stress and evidenced by a significant reduction in the mRNA expression of SOD and GST in a duration-dependent manner. In conclusion: the present study stated that TiO2NPs exposure for long durations had toxic effects on both exocrine and endocrine pancreas mediated by apoptotic and oxidative stress pathways.

doi: https://doi.org/10.1080/01913123.2020.1786203

- Next-generation sequencing of residual cytologic fixative preserved DNA from pancreatic lesions: A pilot study

Cancer cytopathology 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32598087

BACKGROUND: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a sensitive and specific tool in the risk stratification of pancreatic lesions, including cysts. The sensitivity and specificity of EUS-FNA has been shown to improve when cytology is combined with next-generation sequencing (NGS). Ideally, fresh cyst fluid is used for NGS. In this pilot study, we explore the possibility of sequencing DNA derived from residual alcohol-fixed pancreatic aspirates. METHODS: Residual cytologic fixatives (n = 42) from 39 patients who underwent EUS-FNA for pancreatic lesions were collected along with demographics, imaging, and laboratory studies. Samples were designated as nonneoplastic/nonmucinous benign (NB), mucinous cyst (MC), pancreatic ductal adenocarcinoma (PDAC), or well-differentiated neuroendocrine tumor (NET) on the basis of cytopathologic evaluation and sequenced on the Oncomine platform (ThermoFisher Scientific, Waltham, Massachusetts). RESULTS: Ten of 14 (71.4%) MCs exhibited clinically significant variants, including KRAS, GNAS, and TP53. Ten of 15 (66.7%) PDACs had KRAS alterations, and 9 of 15 (60%) showed variants in TP53. No variants were detected in any NETs. Only 1 of 9 (11.1%) NB aspirates showed variants in KRAS and MAP2K. Sequencing of formalin-fixed, paraffin-embedded tissue revealed variants identical to those detected in fixative-derived DNA in 4 of 5 cases (80%). CONCLUSION: Residual DNA from alcohol-fixed aspirates are an underutilized source for NGS. Sequencing residual fixative-derived DNA has the potential to be integrated into the workup of pancreatic aspirates, possibly impacting management.

doi: https://doi.org/10.1002/cncy.22315

- CRABP2 and FABP5 expression levels in diseased and normal pancreas

Annals of diagnostic pathology 2020 Jun;47():151557

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32593808

Recently, stromal targeting, by agents such as All trans retinoic acid (ATRA), has been regarded as a promising avenue for the treatment of pancreatic ductal adenocarcinoma (PDAC). The intra-cellular transportation of ATRA to the nuclear receptors is performed by either: fatty acid binding protein 5 (FABP5) or cellular retinoic acid binding protein 2 (CRABP2), dictating the transcription of downstream genes and, thus, eventual cell phenotype. Here, we explored the levels of each protein, in pancreatic tissues of patients presenting with a range of pancreatic diseases (pancreatic ductal adenocarcinoma (PDAC), chronic pancreatitis (CP), cholangiocarcinoma (CC)). We demonstrate that there is a significantly lower CRABP2 and FABP5 expression in activated fibroblasts or pancreatic stellate cells (PSC) in PDAC, as well as other diseased pancreas as in CC and CP, versus quiescent fibroblasts. The quiescent fibroblasts consistently show a pattern of high FABP5:CRABP2 ratio, whereas PSC in all non-PDAC tissues showed a low FABP5:CRABP2 ratio. PSC in PDAC patients had a range of FABP5:CRABP2 ratios (high, even and low). There was a lower CRABP2 expression in cancerous epithelial cells (PDAC) versus normal epithelial cells. This is also present in other disease states (CP, CC). Contrasting to the patterns seen for fibroblasts, the FABP5 expression in PDAC epithelial cells matched that of the normal epithelial cells. However, the normal epithelial cells had a high FABP5:CRABP2 ratio, compared to the PDAC epithelial cells. These ratios may have correlation with tumor progression, and overall survival. These findings could be confirmed in in vitro cell lysates. CRABP2 and FABP5 levels and ratios could serve as valuable biomarkers.

doi: https://doi.org/10.1016/j.anndiagpath.2020.151557

- Undifferentiated carcinoma with osteoclast-like giant cells of the pancreas harboring KRAS and BRCA mutations: case report and whole exome sequencing analysis

BMC gastroenterology 2020 Jun;20(1):202

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32590950

BACKGROUND: Undifferentiated carcinoma with osteoclast-like giant cells (UC-OGC) is an extremely uncommon pancreatic neoplasm that comprises less than 1% of all exocrine pancreatic tumors. To date, cases and data from whole-exome sequencing (WES) analysis have been reported by specific studies. We report a case of pancreatic UC-OGC with a literature review, and provide novel insights into the molecular characteristics of this tumor entity. CASE PRESENTATION: A 31-year-old male presented with intermittent abdominal pain for several months, and positron emission tomography (PET) showed isolated high metabolic nodules during the pancreatic uncinate process that were likely to be malignant disease. Pathological examination after radical excision revealed UC-OGC associated with poorly differentiated adenocarcinoma at the head of the pancreas. The disease recurred 7.4 months after radical surgery. The KRAS p.G12D (c.35G > A) and somatic BRCA2 p.R2896C (c.8686C > T) mutations were detected by subsequent WES analysis. The patient showed no response to platinum-based systemic chemotherapy, and his condition quickly worsened. He finally died, with an overall survival of 1 year. CONCLUSIONS: As an extremely uncommon tumor entity, UC-OGC is really a unique variant of conventional pancreatic ductal adenocarcinoma due to its similarities, as shown by genomic WES analysis. Clinical examination and molecular analysis by WES could further indicate potential treatment strategies for UC-OGC.

doi: https://doi.org/10.1186/s12876-020-01351-7

- Matrix Metalloproteinase 11 as a Novel Tumor Promoter and Diagnostic and Prognostic Biomarker for Pancreatic Ductal Adenocarcinoma

Pancreas 2020 Jul;49(6):812-821

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32590618

OBJECTIVES: Matrix metalloproteinase 11 (MMP-11) was found to be implicated in tumorigenesis in cancers. However, the significance of MMP-11 in pancreatic ductal adenocarcinoma (PDAC) is unclear. METHODS: In the study, we detected malignant biological behaviors of pancreatic cancer after downregulation of MMP-11. Furthermore, we explored the possible mechanism, and the diagnostic value of serum MMP-11 level was analyzed in 116 patients with pathologically confirmed PDAC. In addition, we explored their prognostic value in PDAC. RESULTS: We observed that MMP-11 could be expressed and activated in the cytoplasm of PDAC cells. Immunohistochemistry staining of PDAC tissues showed that MMP-11 was highly expressed in cancerous ductal epithelium instead of cancer stroma. We found that downregulation of MMP-11 inhibited proliferation of PDAC cell lines. The expression levels of cyclin-dependent kinase 4 and cyclin D1 were downregulated after MMP-11 knockdown. As for its clinical value, the serum level of MMP-11 was shown to be a potent promising diagnostic marker for PDAC. CONCLUSIONS: Matrix metalloproteinase 11 may act as a tumor promoter, playing a positive role in PDAC development. Serum MMP-11 also has great potential to be a promising diagnostic marker for PDAC.

doi: https://doi.org/10.1097/MPA.0000000000001583

- Endoscopic Ultrasound-Guided Fine Needle Aspiration Cytologic Evaluation of Intraductal Papillary Mucinous Neoplasm and Mucinous Cystic Neoplasms of Pancreas

American journal of clinical pathology 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32589187

OBJECTIVES: To evaluate the role of endoscopic ultrasound-guided fine needle aspiration cytology in identifying mucinous cystic lesions (MCLs) in histologically proven cases of intraductal papillary mucinous neoplasm (IPMN) or mucinous cystic neoplasm (MCN) and risk of malignancy associated with each cytologic category based on the Papanicolaou Society of Cytopathology (PSC) guidelines. METHODS: All resected cases with histologic diagnosis of IPMN or MCN at our institution from January 1, 2004, to August 31, 2019, with associated cytology were included. Available cytology slides of nondiagnostic (ND), negative/benign (BN), and atypical cytology (AC) cases were reviewed and reclassified based on the PSC guidelines. RESULTS: A total of 120 cases were identified, including 57 IPMNs with low-grade or moderate dysplasia (LGD/MD) and high-grade dysplasia (HGD), 34 MCNs with LGD/MD or HGD, and 29 IPMNs with invasive malignancy. After cytology slide review and reclassification, we observed that ND and BN cases were paucicellular and lacked ancillary testing (carcinoembryonic antigen levels or KRAS mutation analysis). The risk-of-malignancy rates were 33% for ND, 11% for BN, 28.5% for AC, 17% for MCL, and 100% for suspicious/positive cytologic diagnosis. CONCLUSIONS: A multidisciplinary approach including combined use of cytology and ancillary testing is helpful in establishing a diagnosis of MCL and identifying associated malignancy.

doi: https://doi.org/10.1093/ajcp/aqaa079

- Insulinoma-associated protein 1 immunostaining for various types of neuroendocrine tumors on FNA smears

Cancer cytopathology 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32573984

BACKGROUND: Insulinoma-associated protein 1 (INSM1) has recently emerged as a reliable nuclear immunostaining marker for detecting neuroendocrine tumors (NETs) in paraffin-embedded surgical samples and cytologic cell blocks, but the reliability of INSM1 staining on cytologic smears is understudied. This study investigated the performance of INSM1 staining on cytologic smears for the detection of various NETs in comparison with chromogranin (CG) and synaptophysin (SYN). METHODS: INSM1, CG, and SYN were stained on cytologic smears of 70 NETs, including 20 pancreatic NETs, 10 lung carcinoid tumors, 11 small cell lung carcinomas (SCLCs), 10 medullary thyroid carcinomas, 10 Merkel cell carcinomas, 4 thymic atypical carcinoid tumors, and 5 olfactory neuroblastomas. The detection rate, the percentage of positive cells, and the staining intensity were recorded. RESULTS: The overall detection rate of INSM1 (94%) was higher than the rates of CG (79%) and SYN (89%). The detection rate of INSM1 was higher than the rates of CG and SYN in SCLC, Merkel cell carcinoma, and olfactory neuroblastoma; higher than the rate of CG and equal to the rate of SYN in pancreatic NETs and medullary thyroid carcinoma; equal to the rate of CG and higher than the rate of SYN in thymic atypical carcinoid tumors; and equal to the rate of CG and lower than the rate of SYN in lung carcinoid tumors. INSM1 staining was easier to interpret than CG and SYN staining, especially in high-grade NETs. CONCLUSIONS: INSM1 can be reliably stained on cytologic smears and outperforms CG and SYN in the verification of clinically or radiologically suspected NETs.

doi: https://doi.org/10.1002/cncy.22310

- Alterations in driver genes are predictive of survival in patients with resected pancreatic ductal adenocarcinoma

Cancer 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32573775

BACKGROUND: KRAS, TP53, CDKN2A, and SMAD4 are established driver genes in pancreatic ductal adenocarcinoma (PDAC). This study was aimed at determining whether the mutational status of driver genes and those involved in DNA repair pathways are associated with clinical outcomes for individuals who undergo resection. METHODS: Eligible individuals were those who underwent resection of PDAC and consented to targeted sequencing of their primary tumor via Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT). Genomic alterations were determined on the basis of MSK-IMPACT results from formalin-fixed, paraffin-embedded samples. Associations between genomic alterations and clinical outcomes were assessed. RESULTS: Targeted sequencing was performed on 283 primary tumors resected between 2004 and 2017. The median follow-up was 23 months among survivors. Alterations in KRAS and TP53 were associated with worse overall survival (OS) in comparison to wild type (median for KRAS, 38.8 months [95% CI, 33.0-45.5 months] vs 91.0 months [95% CI, 34.8 months to not available (NA)]; P = .043; median for TP53, 37.4 months [95% CI, 32.1-42.8 months] vs 65.0 months [95% CI, 33.0 months to NA]; P = .035). KRAS G12D mutations were associated with worse OS (median, 31.6 months [95% CI, 25.3-45.5 months] vs 39.2 months [95% CI, 37.4-75.2 months]; P = .012). TP53 truncating mutations (median, 39.6 months [95% CI, 32.4-75.2 months] vs 33.9 months [95% CI, 24.0-39.0 months]; P = .020) and those associated with loss of heterozygosity (median, 26.6 months [95% CI, 21.6-44.2 months] vs 39.2 months [95% CI, 34.5-49.1 months]; P = .048) had decreased OS. TP53 alterations were independently associated with OS in a multivariate analysis (hazard ratio, 1.54; 95% CI, 1.01-2.33; P = .042). Individuals with germline alterations in homologous recombination deficiency (HRD) genes had improved OS in comparison with those without them (median, not reached vs 37.0 months; 95% CI, 33.0-49.8 months; P = .035). CONCLUSIONS: In patients with resected PDAC, genomic alterations in KRAS and TP53 are associated with worse outcomes, whereas alterations in HRD genes are associated with a favorable prognosis. Further studies are needed to better define these alterations as biomarkers in resected PDAC.

doi: https://doi.org/10.1002/cncr.33038

- The utility of immunohistochemical testing for mismatch repair proteins in fine needle aspiration specimens of pancreatic adenocarcinoma

Annals of diagnostic pathology 2020 Jun;47():151552

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32570025

INTRODUCTION: Microsatellite instability (MSI) testing is recommended for all colonic and endometrial carcinomas to screen for Lynch syndrome. The role of MSI testing in pancreatic adenocarcinoma has not been well-established. Screening can be done via immunohistochemical (IHC) staining for mismatch repair (MMR) proteins (MLH1, MSH2, MSH6, PMS2). We report our experience and the clinical utility of MMR IHC on pancreatic adenocarcinomas in fine-needle aspiration (FNA) specimens. MATERIALS AND METHODS: We performed a retrospective review to identify all patients diagnosed with pancreatic adenocarcinoma by FNA at our institution between December 2017 and September 2019. For cases with sufficient tumor cells for testing, the MMR results and morphology were summarized, as well as corresponding clinical information, including age, clinical stage, treatment, and concurrent other cancers. RESULTS: From December 2017 to September 2019, there were a total of 184 pancreatic FNAs with a diagnosis of adenocarcinoma. Of these 184 FNAs, 65 (35%) contained sufficient material in the cell block to perform IHC for MMR. The cell block material was collected in either RPMI or CytoLyt. Poor technical quality precluded interpretation of PMS2 in 4 cases and MSH6 in 2 cases. All other cases showed intact expression of all four proteins. CONCLUSIONS: IHC for MMR proteins can be done on specimens collected in RPMI or CytoLyt, but RPMI appears to be more reliable. None of the pancreatic adenocarcinomas in this study showed loss of MMR protein expression. Routine testing of MMR loss may not be indicated in pancreatic adenocarcinomas in the general patient population.

doi: https://doi.org/10.1016/j.anndiagpath.2020.151552

- The applicability of Papanicolaou Society of Cytopathology system on reporting endoscopic ultrasound guided fine needle aspiration cytology specimens of pancreatic lesions in situations with limited availability of ancillary tests. Experience at a single laboratory

Cytopathology : official journal of the British Society for Clinical Cytology 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32535975

OBJECTIVE: The Papanicolaou Society of Cytopathology (PSC) system of reporting pancreatobiliary cytology is a standardized reporting nomenclature which uses a six-tiered scheme of diagnostic categories utilizing routine microscopy and ancillary tests such as biochemical and molecular analysis of cyst fluids and immunochemistry. The objective of this study was to determine the applicability of the PSC system on endoscopic ultrasound guided fine needle aspiration cytology (EUS-FNAC) samples reported at the cytopathology laboratory, Mubarak Al Kabeer Hospital, in Kuwait with special emphasis on situations with limited availability of ancillary tests. METHODS: 132 cases of EUS-FNAC samples from pancreatic lesions were categorized according to PSC system guidelines after examining the glass slides and reviewing the clinical, imaging and ancillary test findings. These review diagnoses were compared with the diagnoses rendered during initial reporting. Correlation with histopathology reports was done wherever available. RESULTS: In 23 (17.42 %) of 132 cases, recategorization was necessary between initial and reviewed diagnoses. In 16 cases, recategorizations were because of non-analogous categories between initial and reviewed diagnosis. In the remaining seven, they were due to identification of newer cytomorphological and imaging findings or because of issues arising from unavailability of sufficient material for ancillary investigations. CONCLUSION: All cases could be categorized using the PSC system with a moderate number of recategorizations between initial and reviewed diagnoses. In certain circumstances, limited availability of ancillary tests, resulted in non-diagnostic categories whereas in other such circumstances, diagnostic categories could be assigned with certain conceptual modifications to the PSC guidelines.

doi: https://doi.org/10.1111/cyt.12873

- Nondiagnostic fine needle aspirates of the pancreas: A root cause analysis

Cancer cytopathology 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32525623

BACKGROUND: Fine needle aspiration (FNA) of the pancreas is considered the primary and least invasive diagnostic method in the evaluation of pancreatic lesions. A nondiagnostic sample may trigger repeat FNA or a more invasive diagnostic procedure. The goal of this study was to identify the root causes of nondiagnostic samples. METHODS: We performed a retrospective review of FNAs of the pancreas categorized as nondiagnostic at our institution between 2008 and 2019. Medical records and slides were reviewed to identify the features described by imaging, rapid on-site evaluation, fluid chemistry, final cytology diagnosis, and final histology. A root cause analysis was performed using the Ishikawa (or fishbone) diagram and the 5 Whys method. RESULTS: A total of 30 cases were identified: 11 adenocarcinomas, 6 cases of pancreatitis, 4 intraductal papillary mucinous neoplasms, 3 serous cystadenomas, 3 neuroendocrine tumors, 1 mucinous cystic neoplasm, 1 retention cyst, and 1 case of Brunner gland hyperplasia. The root causes identified were: man in 8 cases, machine in 1 case, method in 17 cases, and material in 18 cases. In many cases, more than 1 root cause contributed to the problem. CONCLUSION: Material related errors contributed to the majority of nondiagnostic results and were primarily related to fibrotic cancers, chronic pancreatitis, absence of diagnostic criteria of cystic lesions, and technically challenging cases. Only 1 major interpretation error was identified. Sampling and interpretive errors contributed equally to man-related causes. For mucinous cysts, neoplastic mucin was difficult to identify in liquid-based preparations. Pathologists tended to issue a nondiagnostic categorization when epithelial cells are lacking and particularly when the nature and radiological impression of the cyst was not communicated.

doi: https://doi.org/10.1002/cncy.22301

- Detection of microsatellite instability in a panel of solid tumours with the Idylla MSI Test using extracted DNA

Journal of clinical pathology 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32513848

AIM: During the last few years, determination of microstatellite instability (MSI) status has become a routine part of clinical practice, essentially to detect Lynch syndrome. Recently, MSI testing has increased with the development of immunotherapy and has expanded to a large panel of solid tumours. The aim of our work was to evaluate a fully automated system developed by Biocartis, the Idylla MSI Test, which performs an MSI analysis within 150 min. METHODS: A comparison between pentaplex PCR, immunohistochemistry and Idylla MSI Test was performed in 53 colorectal carcinoma samples, 7 small intestine adenocarcinomas, 15 duodenal and pancreatic adenocarcinomas, 16 gastric tumours, 15 endometrial adenocarcinomas, 5 ovarian carcinomas and 4 cases of urinary tract tumours using extracted DNA. Limit-of-detection (LOD) experiment was also done using a commercial DNA known to harbour MSI phenotype. RESULTS: The overall sensitivity was 94% and the overall specificity was 100%. Two invalid and three false-negative results were observed. Our experiments showed that the amount of DNA loaded into the cartridge was decisive and should be superior to 25 ng. LOD comprised between 4% and 8%. CONCLUSION: Overall, we have demonstrated that the Idylla MSI Test is a rapid and valid option to detect MSI phenotype which can be used in a large panel of solid tumours.

doi: https://doi.org/10.1136/jclinpath-2020-206581

- Next-generation sequencing in residual liquid-based cytology specimens for cancer genome analysis

Diagnostic cytopathology 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32511899

BACKGROUND: Cancer genome profiling of cytology specimens using next-generation sequencing (NGS) requires adequate and good-quality DNA. Genomic examination of cytology samples was conventionally performed on cell block (CB) or smear specimens than on residual liquid-based cytology (LBC) specimens, which are high-quality DNA sources even after long-term storage. METHODS: We estimated tumor fractions of 37 residual LBC specimens, including 30 fine needle aspiration (FNA) samples from the thyroid (12 papillary thyroid carcinomas and two malignant lymphomas), lymph node (13 metastatic carcinomas and one malignant lymphoma), and breast cancer (one phyllodes tumor and one invasive ductal carcinoma), two pancreatic carcinoma samples, and five liquid (ascites, pleural effusion, and cerebrospinal fluid) samples. The DNA was extracted from all samples and subjected to NGS using a customized cancer gene panel comprising 28 cancer-related genes. RESULTS: NGS analysis revealed somatic mutations corresponding to pathological diagnosis with adequate variant allele frequency (VAF) in 24 LBC specimens, which had significantly higher tumor fraction (72.5% ± 4.9%). Ten cases, including the five fluid samples, had very small tumor fractions (7.5% ± 2.3%) to obtain sufficient VAF. Other two samples had high tumor fractions but showed very low VAF, indicating the presence of fusion genes. The remaining one sample yielded no DNA recovery. CONCLUSION: The residual LBC specimens collected by FNA from the thyroid gland and lymph node were verified to carry high tumor fraction and could serve as an alternate source for molecular testing to screen and diagnose cancers without the use of CB or smears.

doi: https://doi.org/10.1002/dc.24511

- Development and Validation of a Modified Eighth AJCC Staging System for Primary Pancreatic Neuroendocrine Tumors

Annals of surgery 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32511134

OBJECTIVE: To improve the prognostic accuracy of the eighth edition of AJCC staging system for pNETs with establishment and validation of a new staging system. BACKGROUND: Validation of the updated eighth AJCC staging system for pNETs has been limited and controversial. METHODS: Data from the SEER registry (1975-2016) (n = 3303) and a multi-institutional database (2000-2016) (n = 825) was used as development and validation cohorts, respectively. A mTNM was proposed by maintaining the eighth AJCC T and M definitions, and the recently proposed N status as N0 (no LNM), N1 (1-3 LNM), and N2 (≥4 LNM), but adopting a new stage classification. RESULTS: The eighth TNM staging system failed to stratify patients with stage I versus IIA, stage IIB versus IIIA, and overall stage I versus II relative to long-term OS in both database. There was a monotonic decrement in survival based on the proposed mTNM staging classification among patients derived from both the SEER (5-year OS, stage I 87.0% vs stage II 80.3% vs stage III 72.9% vs stage IV 57.2%, all P < 0.001), and multi-institutional (5-year OS, stage I 97.6% vs stage II 82.7% vs stage III 78.4% vs stage IV 50.0%, all P < 0.05) datasets. On multivariable analysis, mTNM staging remained strongly associated with prognosis, as the hazard of death incrementally increased with each stage among patients in the 2 cohorts. CONCLUSION: A mTNM pNETs clinical staging system using N0, N1, N2 nodal categories was better at stratifying patients relative to long-term OS than the eighth AJCC staging.

doi: https://doi.org/10.1097/SLA.0000000000004039

- Peribiliary glands pathology in a large series of end-stage alcohol-related liver disease

Virchows Archiv : an international journal of pathology 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32506156

The peribiliary glands are intramural or extramural structures with multiple functions related to bile secretion. The peribiliary glands can develop cystic alterations in several conditions, such as alcohol addiction. Peribiliary cysts can enlarge till being radiologically visible and mimic cancer. We studied 217 consecutive explanted livers for end-stage alcohol-related liver disease from the Pathology Unit of the Liver Unit at the King’s College Hospital in Denmark Hill, with particular focus on peribiliary glands. Our cohort consisted of 31 females and 186 males, with a median age of 51 and of 56 years respectively. 92,2% had established cirrhosis, 73,3% had only alcohol-induced liver disease, whilst 26,7% had other co-morbidities. We found a mild ectasia of the peribiliary glands (<2 mm) in 37,8% and peribiliary cysts (> = 2 mm) in 22,6% of cases. The diameter of the peribiliary glands varied from 1 mm to 8 mm. Inflammation of the peribiliary glands was found in the majority of cases with dilatation (p value = 0,000). 4,6% of the peribiliary cysts had low-grade intraductal papillary neoplasm of the bile ducts confined to the peribiliary glands. Pancreatic heterotopia was found in 10,6% and associated with the presence of ectasia. Our findings fit with what is reported in literature, such as the alcohol-induced damage at the peribiliary glands. Moreover these results underline the possible role of peribiliary glands in the development of the intraductal papillary neoplasm of the bile ducts, the biliary counterpart of the branch type intraductal mucinous neoplasm of the pancreas.

doi: https://doi.org/10.1007/s00428-020-02851-3

- Morphologic Variants of Pancreatic Neuroendocrine Tumors: Clinicopathologic Analysis and Prognostic Stratification

Endocrine pathology 2020 Jun;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32488621

Better prognostication/stratification of pancreatic neuroendocrine tumors (PanNETs) is needed. In this detailed morpheomic study of 163 resected PanNETs, 11 unusual variants, some of which were not previously recognized, and others scarcely documented in the literature, were identified, and their pathologic characteristics were further analyzed. By behavior and clinicopathologic associations, these variants could be grouped into three prognostically different categories. I. More aggressive (20%). Included in this group were the variants that in average showed higher grade and stage and adverse outcome including oncocytic, plasmacytoid, lipid-rich and previously unrecognized hepatoid variants, which often had a more diffuse/broad-band growth pattern, with some also displaying discohesiveness. They were characterized by abundant cytoplasm and often had prominent nucleoli (as seen in metabolically active cells), thus the provisional name “metabolic cell phenotype.” Because of their diversion from classical neuroendocrine cytomorphology, these variants created challenges on original diagnostic workup, particularly hepatoid examples, which revealed Arginase 1/Hep Par-1 expression in 50%. II. Less aggressive (10%). These cases either showed signs of maturation, including nested growth, paraganglioid pattern (which was previously unrecognized), and organoid PanNETs such as “ductulo-insular” growth, or showed symplastic/degenerative changes, and despite their paradoxically disconcerting histology, were more benevolent in behavior. III. Undetermined. There were other variants including mammary tubulolobular-like, pseudoglandular, peliotic, and sclerotic PanNETs, which although diagnostically challenging, their biologic significance could not be determined because of rarity or heterogeneous characteristics. Prognostic associations: Features that were significantly different in the more aggressive group than the less aggressive group were median size (5.0 vs 1.6 cm, p < 0.001), percentage of pT3+T4 cases (72% vs 12%, p < 0.001), Ki67 index (5.3% vs 2.3%, p = 0.001), % G2 and G3 cases (77% vs 27%, p < 0.001), and rate of lymph node and distant metastasis (96% vs 27%, p < 0.001). In stepwise logistic regression model using the 3 established prognosticators of T stage, size, and grade along with morphology, only aggressive-morphology (metabolic cell phenotype) was found to be associated with metastatic behavior with an odds ratio of 5.9 with 95% confidence interval (C.I.) 1.688 to 22.945 and p value 0.007. In conclusion, PanNETs display various morphologic patterns that are not only challenging and important diagnostically but appear to have biologic significance. Tumors with more diffuse growth of cells with nucleoli and abundant cytoplasm and/or discohesion (oncocytic, hepatoid, lipid-rich, plasmacytoid PanNETs), provisionally termed “metabolic cell phenotype,” show aggressive characteristics and are an independent determinant of adverse outcome and thus may require closer post-surgical follow-up, whereas variants with more degenerative or mature features (ductuloinsular, pleomorphic, paraganglioma-like) appear to be more benevolent despite their more atypical and worrisome morphology.

doi: https://doi.org/10.1007/s12022-020-09628-z

- Cancer-associated fibroblasts are a useful cytological finding for diagnosing pancreatic ductal adenocarcinoma

Cytopathology : official journal of the British Society for Clinical Cytology 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32472717

BACKGROUND: Cancer-associated fibroblasts (CAFs) are activated fibroblasts or myofibroblaststhatplay a crucial role in the invasiveness of pancreatic ductal adenocarcinoma (PDAC). In this study, the cytological features and diagnostic significance of CAFsbased on pancreatic duct brushing cytology (PDBC) were evaluated. METHODS: The prevalence of fibrous stroma (FS) including CAFs on PDBC in 42 PDAC cases and 33 benign cases was retrospectively investigated. The average nuclear size of fibroblasts was compared between PDAC and benign cases to distinguish CAFs from normal FS. RESULTS: Overall, FSwas observed in 25 PDAC cases (60%) and 8 benign cases (24%). The average nuclear size of FS in PDAC cases was significantly larger than that in benign cases. From the receiver operating characteristics analysis, the cut-off value of the nuclear size of FS for the diagnosis of PDAC was defined as 10.22µm. FS with nuclei over 10.22µmin size in PDAC cases had clear prominent nucleoli. In contrast, FS in benign cases had no clear nucleoli. Thus, CAFs on PDBC were considered to be FS with nuclei over 10.22µmin size and prominent nucleoli. The presence of CAFs on PDBC had 100% positive predictive value and specificity for the diagnosis of PDAC. CONCLUSIONS: This study suggested that CAFs on PDBC could be distinguished from normal FS by large nuclear size (over 10.22µm) and prominent nucleoli and that CAFs on PDBC may be used for the diagnosis of PDAC.

doi: https://doi.org/10.1111/cyt.12868

- Angiotensin-converting enzyme 2 influences pancreatic and renal function in diabetic mice

Laboratory investigation; a journal of technical methods and pathology 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32472097

Type 1 diabetes is a T-cell mediated autoimmune disease characterized by pancreatic beta cells destruction. Angiotensin-converting enzyme 2 (ACE2), a component of renin-angiotensin system (RAS) has been identified in pancreas from type 2 diabetic mice and its overexpression prevents beta cell dysfunction. We studied the effect of ACE2 deletion on pancreatic and renal function in the nonobese diabetic mice, a model that mimics type 1 diabetes. ACE2-deficient NOD mice and the respective controls were generated. Pancreas function and immunohistochemistry studies were performed. Renal function and RAS gene expression were also analyzed. Renal proximal tubular cells were obtained from these animals to dissect the effect of ACE2 deficiency in these cells. In NOD mice, ACE2 deletion significantly worsened glucose homeostasis, decreased islet insulin content, increased beta cell oxidative stress, and RIPK1-positive islets as compared with control mice. Angiotensin-converting enzyme and angiotensin II type 1 receptor (AT1R) were also increased in ACE2-deficient mice. In kidneys of 30-day diabetic mice, ACE2 deletion decreased podocyte number within the glomeruli, and altered renal RAS gene expression in tubules. ACE2 deletion influenced the expression of fibrosis-related genes in isolated primary renal proximal tubular cells before diabetes onset in NOD mice. Our findings suggest that ACE2 deletion may have a deleterious impact on beta cell and renal function, by promoting oxidative stress and increasing necroptosis mediators. In addition, this effect is accompanied by RAS alterations in both pancreas and renal proximal tubular cells, indicating that ACE2 may exert a renopancreatic protective effect on type 1 diabetes, which is activated before diabetes starts.

doi: https://doi.org/10.1038/s41374-020-0440-5

- Chronic inflammatory changes and oxidative stress in the background of “pancreatic ductal adenocarcinoma concomitant with intraductal papillary mucinous neoplasm”

Virchows Archiv : an international journal of pathology 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32468246

Cases of “pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm” (IPMN) have multiple PDAC lesions more frequently than cases of “PDAC without IPMN”. However, the mechanism of carcinogenesis in this former disease category remains unknown. The main objective of this work was thus to investigate the effects of chronic inflammation on carcinogenesis in PDAC cases. We selected 31 “PDAC concomitant with IPMN” patients and 58 “PDAC without IPMN” patients and pathologically evaluated their background pancreatic parenchyma. Fibrosis and inflammation scores of background pancreas were higher in “PDAC concomitant with IPMN” than in “PDAC without IPMN” (P < 0.0001 and P < 0.0001, respectively), whereas the fatty infiltration score of background pancreas was high in “PDAC without IPMN” (P = 0.0024). Immunohistochemically, the expression of 8-hydroxy-2’-deoxyguanosine (8-OHDG), an oxidative stress marker, in the background pancreas was high in “PDAC concomitant with IPMN” compared with that in “PDAC without IPMN” (P < 0.0001). Chronic inflammation activates oxidative stress in tissue throughout the pancreas and probably confers susceptibility to tumorigenesis in “PDAC concomitant with IPMN”.

doi: https://doi.org/10.1007/s00428-020-02844-2

- Intraductal pancreatic cancer is less responsive than cancer in the stroma to neoadjuvant chemotherapy

Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32457408

Neoadjuvant chemotherapy (NAC) is often the treatment of choice for borderline resectable and locally advanced invasive pancreatic ductal adenocarcinoma (PDAC); however, most cancers only partially respond to therapy. We hypothesized that the location of residual neoplastic cells in resected specimens following NAC could provide a clue as to the mechanisms of resistance. PDAC cells invade the stroma but can also invade back into and spread via the pancreatic ducts, which has been referred to as “cancerization of ducts” (COD). We compared the responsiveness to chemotherapy between PDAC cells in the stroma and PDAC cells in the duct. Pancreatic resections from a total of 174 PDAC patients (NAC, n = 97; immediate surgery, n = 77) were reviewed. On hematoxylin and eosin sections, COD was identified at the same prevalence in both groups (NAC: 50/97 cases, 52%; immediate surgery: 39/77 cases, 51%; p = 0.879, Fisher’s exact test). However, using quantitative image analysis of CK19 immunohistochemistry, we found that the proportion of cancer cells that were intraductal was significantly different between the NAC and immediate surgery groups (median; 12.7% vs. 1.99%, p < 0.0001, Mann-Whitney U test). This proportion was highest in patients with marked therapy responses (36.2%) compared with patients with moderate or poor responses (7.21 & 7.91%). In summary, our data suggest that intraductal components in PDAC are less responsive to chemotherapy than the remainder of the tumor, which could have important implications for therapeutic resistance.

doi: https://doi.org/10.1038/s41379-020-0572-6

- Detailed Analysis of Margin Positivity and the Site of Local Recurrence After Pancreaticoduodenectomy

Annals of surgical oncology 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32451945

BACKGROUND: The association between a positive surgical margin and local recurrence after resection of pancreatic adenocarcinoma (PDAC) has been reported. Assessment of the location of the a positive margin and the specific site of local recurrence has not been well described. METHODS: A prospectively maintained database was queried for patients who underwent R0/R1 pancreaticoduodenectomy for PDAC between 2000 and 2015. The pancreatic, posterior, gastric/duodenal, anterior peritoneal, and bile duct margins were routinely assessed. Postoperative imaging was reviewed for the site of first recurrence, and local recurrence was defined as recurrence located in the remnant pancreas, surgical bed, or retroperitoneal site outside the surgical bed. RESULTS: During the study period, 891 patients underwent pancreaticoduodenectomy, and 390 patients had an initial local recurrence with or without distant metastases. The 5-year cumulative incidence of local recurrence by site included the remnant pancreas (4%; 95% confidence interval [CI], 3-5%), the surgical bed (35%; 95% CI, 32-39%), and other regional retroperitoneal site (4%; 95% CI, 3-6%). In the univariate analysis, positive posterior margin (hazard ratio [HR], 1.50; 95% CI, 1.17-1.91; p = 0.001) and positive lymph nodes (HR, 1.36; 95% CI, 1.06-1.75; p = 0.017) were associated with surgical bed recurrence, and in the multivariate analysis, positive posterior margin remained significant (HR, 1.40; 95% CI, 1.09-1.81; p = 0.009). An isolated local recurrence was found in 197 patients, and a positive posterior margin was associated with surgical bed recurrence in this subgroup (HR, 1.51; 95% CI, 1.08-2.10; p = 0.016). CONCLUSION: In this study, the primary association between site of margin positivity and site of local recurrence was between the posterior margin and surgical bed recurrence. Given this association and the limited ability to modify this margin intraoperatively, preoperative assessment should be emphasized.

doi: https://doi.org/10.1245/s10434-020-08600-9

- Beyond Stiffness: Collagen Signaling in Pancreatic Cancer and Pancreas Regeneration

The American journal of pathology 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32450151

This commentary highlights the article by Ruggeri et al that reports the importance of discoidin domain receptor 1 in tissue homeostasis in pancreatic injury and pancreatic ductal adenocarcinoma pathogenesis.

doi: https://doi.org/10.1016/j.ajpath.2020.05.005

- Adenosquamous Carcinoma of the Pancreas Comprise a Heterogeneous Group of Tumors With the Worst Outcome: A Clinicopathological Analysis of 25 Cases Identified in 562 Pancreatic Carcinomas Resected With Curative Intent

Pancreas 2020 5;49(5):683-691

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32433407

OBJECTIVES: Information of the clinicopathological characteristics and outcome data of patients with adenosquamous carcinoma of the pancreas (ASCAP) remains limited. This study’s aim is to describe the clinical, pathological, and molecular characteristics of 25 resected ASCAPs. METHODS: Of all 25 cases, patient characteristics, follow-up data, and pathological/immunohistological features were reviewed and analyzed. RESULTS: In this 3-institutional retrospective analysis of 562 pancreatic cancer patients, we identified 25 cases with histologically confirmed ASCAP (4.4%). Follow-up was available in 21 ASCAP and 50 pancreatic ductal adenocarcinoma control patients with a median overall survival of 8.2 and 21 months, respectively. Age, tumor size, localization in the tail, lymph node status, and resection margin seem to be the most significant factors of survival in our ASCAP cohort. In contrast to pancreatic ductal adenocarcinoma, positive expression of p63, keratins K5/14, and the epidermal growth factor receptor are a robust marker profile of these tumors. CONCLUSIONS: Adenosquamous carcinoma of the pancreas comprises a group of neoplasms in which stage and adverse morphological features contribute to its bad prognosis. Further work must be pursued to improve detection and treatment options to reduce mortality. Specifically, differences in biology might become a target for the development of possible therapies.

doi: https://doi.org/10.1097/MPA.0000000000001548

- Clinical Utility of Histological and Radiological Evaluations of Tumor Necrosis for Predicting Prognosis in Pancreatic Cancer

Pancreas 2020 5;49(5):634-641

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32433400

OBJECTIVES: Tumor necrosis is often found in pancreatic ductal adenocarcinoma (PDAC). Objective histological assessment and adequate radiological detection of necrosis could be used as biomarkers for therapeutic decision. However, standardized clinical utility of necrosis remains unknown. Here, we aimed to determine the prognostic potential of histological and radiological evaluations of necrosis. METHODS: We investigated histological necrosis in 221 patients, who underwent surgery for PDAC, and classified its size as small (≤5 mm) or large (>5 mm). We also evaluated poorly enhanced areas on preoperative computed tomography to assess their ability for predicting histological necrosis and postoperative prognosis. RESULTS: Tumor necrosis was found in 115 patients (52%) and was related to tumor area, lymph node metastasis, and lymphovascular invasion. Size of necrosis was significantly associated with tumor area, perimeter of necrosis, circularity of necrosis, number of ruptured cancer glands, and presence of collagen bundle (P < 0.05 for all). Both presence of necrosis and their size were strongly correlated to postoperative prognosis. Patients with poorly enhanced areas showed worse prognosis (P < 0.01). CONCLUSIONS: Our findings underline the capacity of histological and radiological assessment of tumor necrosis for prognosis prediction in PDAC.

doi: https://doi.org/10.1097/MPA.0000000000001539

- Negative prognostic impact of PD-L1 expression in tumor cells of undifferentiated (anaplastic) carcinoma with osteoclast-like giant cells of the pancreas: study of 13 cases comparing ductal pancreatic carcinoma and review of the literature

Virchows Archiv : an international journal of pathology 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32424767

Pancreatic carcinoma remains one of the leading cancer-related causes of death worldwide and is generally characterized by a dismal prognosis and limited potential for oncologic treatment. A rare subvariant of pancreatic cancer, undifferentiated carcinoma with osteoclast-like giant cells (UCOGC), has an unpredictable prognosis according to many previous studies, with unexpectedly long survival in individual cases. In this study, we collected, retrospectively, 13 cases of well-documented UCOGCs and performed immunohistochemistry focused on the expression of the programmed death-ligand 1 (PD-L1) and several other potential therapeutic and predictive markers (PanTRK, p53, MSH2, PMS2, and the number of tumor-infiltrating lymphocytes), to explore their correlation with the follow-up of the patients. As a control group, we examined 24 cases of conventional pancreatic ductal adenocarcinoma (PDAC). In our results, PanTRK was negative in all 24 cases. P53 did not show any significant differences between UCOGCs and PDACs, and the entire cohort was MSH2, MLH1, PMS2, and MSH6 positive. Significant differences were present in the analysis of PD-L1: UCOGCs were found to express PD-L1 significantly more frequently and have a higher number of tumor-infiltrating lymphocytes than PDAC. The expression of PD-L1 was related to significantly shorter survival in patients with UCOGC and in the entire cohort. Patients with PD-L1 negative UCOGCs displayed surprisingly long survival in comparison to PD-L1 positive UCOGCs and PDACs (both PD-L1+ and PD-L1-). We compared our results with previously published data, and, after statistical analysis, we were able to identify PD-L1 as an effective prognostic marker of UCOGC and suggest a strong need for a clinical trial of immune checkpoint immunotherapy in patients with advanced PD-L1 positive UCOGC.

doi: https://doi.org/10.1007/s00428-020-02830-8

- Grading Solid Pseudopapillary Tumors of the Pancreas: the Fudan Prognostic Index

Annals of surgical oncology 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32424583

BACKGROUND: Ki-67 has been shown to predict outcome of patients with solid pseudopapillary tumor of the pancreas (SPTP) but has not been incorporated into a formal classification system to predict recurrence-free survival (RFS). METHODS: This is a retrospective cohort study of patients with histologically confirmed diagnosis of SPTP who had at least 1 year of follow-up at two tertiary academic centers. Survival data were assessed by Kaplan-Meier method and multivariable Cox regression model. Prognostic performance was compared among various systems. RESULTS: A total of 193 consecutive patients were included, ranging in age from 12 to 70 years (median 33 years). Seven patients (3.6%) developed tumor recurrence. The 3-, 5-, and 10-year RFS rates were estimated at 96.9%, 96.1%, and 94.8%, respectively. For the AJCC staging system, patients with stage I had similar prognosis to those with stage II. For the ENETS staging system, patients with stage I to III had similar prognosis. Grade based on Ki-67 was superior to both the AJCC and ENETS systems for predicting survival. Multivariate analysis revealed that large tumor size [> 10 cm; hazard ratio (HR), 6.177 95% confidence interval (CI), 1.289-29.603; P = 0.023] and Ki-67 (HR, 17.199 95% CI, 4.001-73.930; P < 0.001) were independent predictors for RFS. The Fudan Prognostic Index based on the combination of Ki-67 and tumor size showed excellent discrimination for RFS and was more accurate and informative than other grading/staging systems. CONCLUSION: The Fudan Prognostic Index better predicts RFS compared with either Ki-67 alone or the current AJCC and ENETS TNM-based staging systems.

doi: https://doi.org/10.1245/s10434-020-08626-z

- Guidelines on the histopathology of chronic pancreatitis. Recommendations from the working group for the international consensus guidelines for chronic pancreatitis in collaboration with the International Association of Pancreatology, the American Pancreatic Association, the Japan Pancreas Society, and the European Pancreatic Club

Pancreatology : official journal of the International Association of Pancreatology (IAP) … [et al.] 2020 Jun;20(4):586-593

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32414657

BACKGROUND: Chronic pancreatitis is a complex multifactorial fibro-inflammatory disease. Consensus guidelines are needed for the histopathological evaluation of non-autoimmune chronic pancreatitis (CP). METHODS: An international working group with experts on the histopathology of CP evaluated 15 statements generated from evidence on seven key clinically relevant questions. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the level of evidence available for each statement. To determine the level of agreement, the working group voted on the statements for strength of agreement, using a nine-point Likert scale, and Cronbach’s alpha reliability coefficients were calculated. RESULTS: Strong consensus was obtained for 12 statements relating to all seven key questions including that: the cardinal features of CP are the triad of fibrosis, loss of acinar tissue and duct changes; there are no unique histopathological features that distinguish the different aetiologies of CP; clinical history and laboratory investigations, including genetic testing, are important in establishing the aetiology of CP; there is no reproducible and universally accepted histological grading system for assessing severity of CP, although classification as “mild”, “moderate” and “severe” is usually applied; scoring systems for fibrosis are not validated for clinical use; asymptomatic fibrosis is a common finding associated with ageing, and not necessarily evidence of CP; there are no obvious diagnostic macroscopic features of early CP; histopathology is not the gold standard for the diagnosis of CP; and cytology alone is not a reliable method for the diagnosis of CP. CONCLUSIONS: Cardinal histopathological features of CP are well-defined and internationally accepted and pathological assessment is relevant for the purpose of differential diagnosis with other pancreatic diseases, especially cancer. However, a reliable diagnosis of CP requires integration of clinical, laboratory and imaging features and cannot be made by histology alone.

doi: https://doi.org/10.1016/j.pan.2020.04.009

- Ki-67 proliferation index in neuroendocrine tumors: Can augmented reality microscopy with image analysis improve scoring?

Cancer cytopathology 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32401429

BACKGROUND: The Ki-67 index is important for grading neuroendocrine tumors (NETs) in cytology. However, different counting methods exist. Recently, augmented reality microscopy (ARM) has enabled real-time image analysis using glass slides. The objective of the current study was to compare different traditional Ki-67 scoring methods in cell block material with newer methods such as ARM. METHODS: Ki-67 immunostained slides from 50 NETs of varying grades were retrieved (39 from the pancreas and 11 metastases). Methods with which to quantify the Ki-67 index in up to 3 hot spots included: 1) “eyeball” estimation (EE); 2) printed image manual counting (PIMC); 3) ARM with live image analysis; and 4) image analysis using whole-slide images (WSI) (field of view [FOV] and the entire slide). RESULTS: The Ki-67 index obtained using the different methods varied. The pairwise kappa results varied from no agreement for image analysis using digital image analysis WSI (FOV) and histology to near-perfect agreement for ARM and PIMC. Using surgical pathology as the gold standard, the EE method was found to have the highest concordance rate (84.2%), followed by WSI analysis of the entire slide (73.7%) and then both the ARM and PIMC methods (63.2% for both). The PIMC method was the most time-consuming whereas image analysis using WSI (FOV) was the fastest method followed by ARM. CONCLUSIONS: The Ki-67 index for NETs in cell block material varied by the method used for scoring, which may affect grade. PIMC was the most time-consuming method, and EE had the highest concordance rate. Although real-time automated counting using image analysis demonstrated inaccuracies, ARM streamlined and hastened the task of Ki-67 quantification in NETs.

doi: https://doi.org/10.1002/cncy.22272

- Amyloid-Rich Pancreatic Neuroendocrine Tumors: a Potential Diagnostic Pitfall in Endoscopic Ultrasound-Guided Fine Needle Aspiration Cytology (EUS-FNAC)

Endocrine pathology 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32399832

Pancreatic neuroendocrine tumors (PanNETs) are rare neoplasms that include even rarer variants that may pose different diagnostic problems, especially in fine needle aspiration cytology (FNAC). We describe the diagnostic clues of the amyloid-rich variant of PanNETs in endoscopic ultrasound (EUS)-guided fine needle aspiration cytology (EUS-FNAC). Three cases of PanNETs with an amyloid-rich stromal component were retrieved and retrospectively reviewed. For every case, the pancreatic lesion was investigated by a EUS-FNAC procedure. The final diagnosis was supported by immunocytochemistry and Congo red staining. All cases had similar EUS-FNAC features: neoplastic cells were entrapped in an eosinophilic, homogeneous dense and amorphous matrix. The neuroendocrine nature was confirmed by immunoexpression of synaptophysin and chromogranin A, while the amorphous stroma was characterized as amyloid based on positive Congo red staining. Regarding the hormonal profile, no insulin or proinsulin reactivity was observed, but all cases were diffusely positive for amylin. The diagnosis of uncommon variants of PanNETs, such as the amyloid-rich, is challenging especially in EUS-FNAC procedures because of a unique and misleading morphology, potentially mimicking fibrotic conditions and amyloid deposition within systemic amyloidosis. In cytology specimens, the presence of amorphous material requires amyloid deposition to be considered in the differential diagnosis of pancreatic neoplasms with neuroendocrine phenotype.

doi: https://doi.org/10.1007/s12022-020-09625-2

- Long Survival and Prolonged Remission after Surgery and Chemotherapy in a Metastatic Mismatch Repair Deficient Pancreatic Neuroendocrine Carcinoma with MLH1/PMS2 Immunodeficiency and Minimal Microsatellite Shift

Endocrine pathology 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32388775

Pancreatic neuroendocrine carcinomas (NECs) are rare and very aggressive neoplasms with dismal prognosis, especially when metastatic or with negative prognostic factors, such as vascular invasion. To the best of our knowledge, no case of pancreatic NEC with mismatch repair deficiency has been reported to date. We describe a 62-year-old patient who underwent pancreaticoduodenectomy for a NEC located in the pancreatic head, with peripancreatic lymph node metastases. Tumor necrosis was prominent and the Ki67 proliferative index was 60%. One year after the diagnosis, the patient experienced recurrence with a left supraclavicular lymph node metastasis, which was surgically removed, followed by standard cisplatin-etoposide chemotherapy. Neoplastic cells showed combined loss of expression of MLH1 and PMS2 in both primary tumor and lymph node metastasis. Microsatellite instability (MSI) test using a mononucleotide repeats pentaplex PCR (BAT-25, BAT-26, NR-21, NR-22, and NR-24) revealed minimal mononucleotide shifts showing deletion of less than 3 bp at NR-21, BAT-26, NR-24, and NR-22 loci. MLH1 methylation analysis revealed absence of the gene promoter methylation. BRAF and KRAS mutations were not detected. In gut, NECs’ mismatch repair deficiency phenotype has been reported in about 10% of cases, and it represents an independent factor of more favorable outcome. Likewise, our patient is currently alive with a follow-up of more than 12 years after pancreaticoduodenectomy, by itself an unexpected finding for such an aggressive neoplasm.

doi: https://doi.org/10.1007/s12022-020-09622-5

- Simple mucinous cysts of the pancreas have heterogeneous somatic mutations

Human pathology 2020 Jul;101():1-9

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32380013

Simple mucinous cysts of the pancreas have an epithelial lining resembling pancreatic intraepithelial neoplasia but may have a clinical presentation similar to premalignant mucinous neoplasms such as intraductal papillary mucinous neoplasms. Whether the epithelial lining shares genomic alterations with other pancreatic preinvasive neoplasms such as PanIN and intraductal papillary mucinous neoplasm has not been determined. We performed targeted sequencing analysis using a custom-designed MiSeq panel including the full coding regions of 18 pancreatic cancer genes on 13 clinically and pathologically well-characterized simple mucinous cysts. We detected 59 mutations in 15 genes in the cohort, with a median of 4 mutations per cyst (range = 0-16 mutations per cyst). The mutated genes and rate of detected mutations were as follows: KMT2C (MLL3) (62%), KRAS (15%), BRAF (8%), RNF43 (8%), CDKN2a (8%), TP53 (15%), and SMAD4 (8%). No GNAS mutations were detected. Four cases (31%) had no mutations detected. These findings place the majority of simple mucinous cysts of the pancreas in the spectrum of early, low-grade mucinous neoplasia, albeit with a different spectrum of genomic alterations compared with PanIN and intraductal papillary mucinous neoplasm.

doi: https://doi.org/10.1016/j.humpath.2020.04.006

- Autophagy promotes immune evasion of pancreatic cancer by degrading MHC-I

Nature 2020 05;581(7806):100-105

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32376951

Immune evasion is a major obstacle for cancer treatment. Common mechanisms of evasion include impaired antigen presentation caused by mutations or loss of heterozygosity of the major histocompatibility complex class I (MHC-I), which has been implicated in resistance to immune checkpoint blockade (ICB) therapy1-3. However, in pancreatic ductal adenocarcinoma (PDAC), which is resistant to most therapies including ICB4, mutations that cause loss of MHC-I are rarely found5 despite the frequent downregulation of MHC-I expression6-8. Here we show that, in PDAC, MHC-I molecules are selectively targeted for lysosomal degradation by an autophagy-dependent mechanism that involves the autophagy cargo receptor NBR1. PDAC cells display reduced expression of MHC-I at the cell surface and instead demonstrate predominant localization within autophagosomes and lysosomes. Notably, inhibition of autophagy restores surface levels of MHC-I and leads to improved antigen presentation, enhanced anti-tumour T cell responses and reduced tumour growth in syngeneic host mice. Accordingly, the anti-tumour effects of autophagy inhibition are reversed by depleting CD8+ T cells or reducing surface expression of MHC-I. Inhibition of autophagy, either genetically or pharmacologically with chloroquine, synergizes with dual ICB therapy (anti-PD1 and anti-CTLA4 antibodies), and leads to an enhanced anti-tumour immune response. Our findings demonstrate a role for enhanced autophagy or lysosome function in immune evasion by selective targeting of MHC-I molecules for degradation, and provide a rationale for the combination of autophagy inhibition and dual ICB therapy as a therapeutic strategy against PDAC.

doi: https://doi.org/10.1038/s41586-020-2229-5

- International Consensus Guidelines for Risk Factors in Chronic Pancreatitis. Recommendations from the working group for the international consensus guidelines for chronic pancreatitis in collaboration with the International Association of Pancreatology, the American Pancreatic Association, the Japan Pancreas Society, and European Pancreatic Club

Pancreatology : official journal of the International Association of Pancreatology (IAP) … [et al.] 2020 Jun;20(4):579-585

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32376198

BACKGROUND: Chronic pancreatitis (CP) is a complex inflammatory disease with remarkably impaired quality of life and permanent damage of the pancreas. This paper is part of the international consensus guidelines on CP and presents the consensus on factors elevating the risk for CP. METHODS: An international working group with 20 experts on CP from the major pancreas societies (IAP, APA, JPS, and EPC) evaluated 14 statements generated from evidence on four questions deemed to be the most clinically relevant in CP. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the level of evidence available per statement. To determine the level of agreement, the working group voted on the 14 statements for strength of agreement, using a nine-point Likert scale in order to calculate Cronbach’s alpha reliability coefficient. RESULTS: Strong consensus and agreement were obtained for the following statements: Alcohol, smoking, and certain genetic alterations are risk factors for CP. Past history, family history, onset of symptoms, and life-style factors including alcohol intake and smoking history should be determined. Alcohol consumption dose-dependently elevates the risk of CP up to 4-fold. Ever smokers, even smoking less than a pack of cigarettes per day, have an increased risk for CP, as compared to never smokers. CONCLUSIONS: Both genetic and environmental factors can markedly elevate the risk for CP. Therefore, health-promoting lifestyle education and in certain cases genetic counselling should be employed to reduce the incidence of CP.

doi: https://doi.org/10.1016/j.pan.2020.03.014

- Prognostic Impact of Pancreatic Invasion in Duodenal Carcinoma: A Single-Center Experience

Annals of surgical oncology 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32367502

BACKGROUND: The prognostic factors for duodenal carcinoma (DC) remain unclear because of its rarity. This study aimed to investigate the prognostic impact of pancreatic invasion (PI) on postoperative survival for patients with DC. METHODS: This study retrospectively analyzed 86 patients with DC, including 18 patients with PI, who underwent surgical resection between October 2002 and March 2018. The clinicopathologic features and survival outcomes of these patients were investigated to identify the prognostic factors in DC. The long-term survival for the DC patients with PI was compared with that for the patients who underwent resection for resectable pancreatic head carcinoma (RPHC) during the same period. RESULTS: The median survival time (MST) for the DC patients with PI was 25.7 months, which was significantly worse than for the patients with T2 or deeper DC without PI (p = 0.010). The multivariate analysis showed that the independent prognostic factors were PI (hazard ratio [HR] 7.59; p = 0.019) and lymph node metastasis (LNM) (HR 5.01; p = 0.026). The MST for the DC patients with PI did not differ significantly from that for the RPHC patients treated without adjuvant chemotherapy (p = 0.135). Comparable rates of microscopic venous invasion and hematogenous metastasis were observed for the DC patients with PI and the RPHC patients. CONCLUSIONS: Pancreatic invasion was an independent prognostic factor in DC. The survival outcomes for the DC patients with PI did not differ from those for the patients with RPHC, which was associated with a high rate of hematogenous recurrence.

doi: https://doi.org/10.1245/s10434-020-08512-8

- Histopathological and Immunophenotypic Changes of Pancreatic Neuroendocrine Tumors after Neoadjuvant Peptide Receptor Radionuclide Therapy (PRRT)

Endocrine pathology 2020 Jun;31(2):119-131

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32361926

Peptide Receptor Radionuclide Therapy (PRRT) is an emerging therapeutic option for pancreatic neuroendocrine tumors (PanNETs). A possible role for PRRT as a neoadjuvant agent is still largely undetermined, explored only in case reports or small case series. Likewise, the histopathological and immunophenotypic changes induced by PRRT are poorly characterized. In the present study, 24 patients who underwent neoadjuvant PRRT on the basis of their disease’s characteristics were retrospectively matched with 24 patients who underwent upfront surgery. A comprehensive morphological and immunohistochemical evaluation was conducted to identify the differences in the two groups. The most significant findings were that the total percentage of stroma increased significantly in patients who underwent PRRT (p < 0.0001) and the characteristics of the stroma were different in the two groups. The somatostatin receptors type 2A (SSTR2A) were retained in most patients (87%) after PRRT. The density of CD163+ M2-polarized macrophages was greater in the PRRT group (p = 0.022), and M2-polarized macrophages tended to assume an epithelioid morphology (p = 0.043). In the neoadjuvant PRRT group, none of the histological parameters considered were associated with progression-free survival (PFS). Neoadjuvant PRRT in PanNETs is associated with reduced tumor diameter, an increased percentage of stroma, preserved SSTR2A expression in most of the cases, and an increased CD163+ M2-polarized macrophages density.

doi: https://doi.org/10.1007/s12022-020-09623-4

- Frequency of mismatch repair deficiency in pancreatic ductal adenocarcinoma

Pathology, research and practice 2020 Jun;216(6):152985

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32360245

Pancreatic ductal adenocarcinoma (PDAC) has an ominous prognosis and there are only few treatment options. It is therefore crucial to investigate possible predictive markers that may improve the treatment of this disease. Mismatch repair (MMR) deficiency (d-MMR), meaning MMR protein loss (l-MMR) and/or microsatellite instability (MSI), is predictive of response to immunotherapy, but its frequency has to our knowledge not been elucidated in Scandinavian PDACs. Our aims were to examine the frequency of d-MMR in a Danish cohort of PDACs. We constructed multi-punch tissue microarrays (TMAs) using primary tumor tissue. Immunohistochemistry (IHC) for the DNA MMR proteins MLH1, MSH2, MSH6 and PMS2 was performed, and their expression was evaluated using a scoring system from 0 to 4. If the overall score was between 0-2 or if IHC was inconclusive for technical reasons, IHC on whole-tissue sections and MSI using PCR was performed. A final score of 0, 1-2 or 3-4 defined the tumor as l-MMR, MMR reduced (r-MMR) or MMR proficient. In total, 4/164 (2.4 %), 2/164 (1.2 %) and 3/164 (1.8 %) were l-MMR, r-MMR, or inconclusive based on IHC. MSI testing of these specimens showed that two of the four l-MMR tumors were MSI-high, while the remaining cases were microsatellite stable (MSS). In conclusion, in this study of Danish PDACss, d-MMR was found in a small proportion of the tumors. For these patients, individualized treatment using immunotherapy could be considered.

doi: https://doi.org/10.1016/j.prp.2020.152985

- RAF1 rearrangements are common in pancreatic acinar cell carcinomas

Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 2020 May;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32358589

There is now evidence that gene fusions activating the MAPK pathway are relatively common in pancreatic acinar cell carcinoma with potentially actionable BRAF or RET fusions being found in ~30%. We sought to investigate the incidence of RAF1 fusions in pancreatic malignancies with acinar cell differentiation. FISH testing for RAF1 was undertaken on 30 tumors comprising 25 ‘pure’ acinar cell carcinomas, 2 mixed pancreatic acinar-neuroendocrine carcinomas, 1 mixed acinar cell-low grade neuroendocrine tumor and 2 pancreatoblastomas. RAF1 rearrangements were identified in 5 cases and confirmed by DNA and RNA sequencing to represent oncogenic fusions (GATM-RAF1, GOLGA4-RAF1, PDZRN3-RAF1, HERPUD1-RAF1 and TRIM33-RAF1) and to be mutually exclusive with BRAF and RET fusions, as well as KRAS mutations. Large genome-wide copy number changes were common and included 1q gain and/or 1p loss in all five RAF1 FISH-positive acinar cell carcinomas. RAF1 expression by immunohistochemistry was found in 3 of 5 (60%) of fusion-positive cases and no FISH-negative cases. Phospho-ERK1/2 expression was found in 4 of 5 RAF1-fusion-positive cases. Expression of both RAF1 and phospho-ERK1/2 was heterogeneous and often only detected at the tumor-stroma interface, thus limiting their clinical utility. We conclude that RAF1 gene rearrangements are relatively common in pancreatic acinar cell carcinomas (14.3% to 18.5% of cases) and can be effectively identified by FISH with follow up molecular testing. The combined results of several studies now indicate that BRAF, RET or RAF1 fusions occur in between one third and one-half of these tumors but are extremely rare in other pancreatic malignancies. As these fusions are potentially actionable with currently available therapies, a strong argument can be made to perform FISH or molecular testing on all pancreatic acinar cell carcinomas.

doi: https://doi.org/10.1038/s41379-020-0545-9

- Genetic and clinical correlates of entosis in pancreatic ductal adenocarcinoma

Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 2020 Apr;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32350415

Entosis is a type of regulated cell death that promotes cancer cell competition. Though several studies have revealed the molecular mechanisms that govern entosis, the clinical and genetic correlates of entosis in human tumors is less well understood. Here we reviewed entotic cell-in-cell (CIC) patterns in a large single institution sequencing cohort (MSK IMPACT clinical sequencing cohort) of more than 1600 human pancreatic ductal adenocarcinoma (PDAC) samples to identify the genetic and clinical correlates of this cellular feature. After case selection, 516 conventional PDACs and 21 ASCs entered this study and ~45,000 HPFs (median 80 HPFs per sample) were reviewed; 549 entotic-CICs were detected through our cohort. We observed that entotic-CIC occurred more frequently in liver metastasis compared with primary in PDAC. Moreover, poorly differentiated adenocarcinoma or adenosquamous carcinoma had more entotic-CIC than well or moderately differentiated adenocarcinoma. With respect to genetic features TP53 mutations, KRAS amplification, and MYC amplification were significantly associated with entosis in PDAC tissues. From a clinical standpoint entotic CICs were independently associated with a poor prognosis by multivariate Cox regression analysis when considering all cases or primary PDACs specifically. These results provide a contextual basis for understanding entosis in PDAC, a highly aggressive cancer for which molecular insights are needed to improve survival.

doi: https://doi.org/10.1038/s41379-020-0549-5

- Comprehensive characterisation of pancreatic ductal adenocarcinoma with microsatellite instability: histology, molecular pathology and clinical implications

Gut 2020 Apr;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32350089

OBJECTIVE: Recently, tumours with microsatellite instability (MSI)/defective DNA mismatch repair (dMMR) have gained considerable interest due to the success of immunotherapy in this molecular setting. Here, we aim to clarify clinical-pathological and/or molecular features of this tumour subgroup through a systematic review coupled with a comparative analysis with existing databases, also providing indications for a correct approach to the clinical identification of MSI/dMMR pancreatic ductal adenocarcinoma (PDAC). DESIGN: PubMed, SCOPUS and Embase were searched for studies reporting data on MSI/dMMR in PDAC up to 30 November 2019. Histological and molecular data of MSI/dMMR PDAC were compared with non-MSI/dMMR PDAC and with PDAC reference cohorts (including SEER database and The Cancer Genome Atlas Research Network - TCGA project). RESULTS: Overall, 34 studies with 8323 patients with PDAC were included in the systematic review. MSI/dMMR demonstrated a very low prevalence in PDAC (around 1%-2%). Compared with conventional PDAC, MSI/dMMR PDAC resulted strongly associated with medullary and mucinous/colloid histology (p<0.01) and with a KRAS/TP53 wild-type molecular background (p<0.01), with more common JAK genes mutations. Data on survival are still unclear. CONCLUSION: PDAC showing typical medullary or mucinous/colloid histology should be routinely examined for MSI/dMMR status using specific tests (immunohistochemistry, followed by MSI-PCR in cases with doubtful results). Next-generation sequencing (NGS) should be adopted either where there is limited tissue or as part of NGS tumour profiling in the context of precision oncology, acknowledging that conventional histology of PDAC may rarely harbour MSI/dMMR.

doi: https://doi.org/10.1136/gutjnl-2020-320726

- Discoidin Domain Receptor 1 (DDR1) Is Necessary for Tissue Homeostasis in Pancreatic Injury and Pathogenesis of Pancreatic Ductal Adenocarcinoma

The American journal of pathology 2020 Apr;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32339496

Pancreatic ductal adenocarcinoma (PDA) and chronic pancreatitis are characterized by a dense collagen-rich desmoplastic reaction. Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase activated by collagens that can regulate cell proliferation, migration, adhesion, and remodeling of the extracellular matrix. To address the role of DDR1 in PDA, Ddr1-null (Ddr-/-) mice were crossed with the KrasG12D/+; Trp53R172H/+; Ptf1aCre/+ (KPC) model of metastatic PDA. Ddr1-/-; KPC mice progress to differentiated PDA but resist progression to poorly differentiated cancer compared with KPC control mice. Strikingly, severe pancreatic atrophy accompanied tumor progression in Ddr1-/-; KPC mice. To further explore the effects of Ddr1 ablation, Ddr1-/- mice were crossed with the KrasG12D/+; Ptf1aCre/+ neoplasia model and subjected to cerulein-induced experimental pancreatitis. Similar to KPC mice, tissue atrophy was a hallmark of both neoplasia and pancreatitis models in the absence of Ddr1. Compared with controls, Ddr1-/- models had increased acinar cell dropout and reduced proliferation with no difference in apoptotic cell death between control and Ddr1-/- animals. In most models, organ atrophy was accompanied by increased fibrillar collagen deposition, suggesting a compensatory response in the absence of this collagen receptor. Overall, these data suggest that DDR1 regulates tissue homeostasis in the neoplastic and injured pancreas.

doi: https://doi.org/10.1016/j.ajpath.2020.03.020

- Does IgG4 level evaluation in pancreatic mass play role in avoiding major surgery in uncertain presentation: A case report

Indian journal of pathology & microbiology 2020 4;63(2):282-285

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32317534

A 66-year-old male presented with chief complaints of anorexia associated with mild dull, intermittent epigastric pain for 6 months. The patient was a known diabetic on oral hypoglycemic and on routine checkup was found to have deranged liver function profile. On radiology, an ill-defined hypoechoic enhancing lesion involving head, neck, and uncinate process of pancreas was noted. Whipple’s pancreaticodudenectomy was done and reported as IgG4-related autoimmune pancreatitis. Later, IgG (slightly) and IgG4 were found to be markedly raised. We report this case to highlight the importance of IgG4 evaluation prior to major surgery in uncertain pancreatic mass.

doi: https://doi.org/10.4103/IJPM.IJPM_289_19

- Does Site Matter? Impact of Tumor Location on Pathologic Characteristics, Recurrence, and Survival of Resected Pancreatic Ductal Adenocarcinoma

Annals of surgical oncology 2020 Apr;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32307617

BACKGROUND: The authors hypothesized that in resected pancreatic adenocarcinoma (PDAC), pathologic characteristics, oncologic outcomes, prognostic factors, and the accuracy of the American Joint Committee on Cancer (AJCC) staging system might differ based on tumor location. METHODS: Patients undergoing pancreatectomy for PDAC at two academic institutions from 2000 to 2015 were retrieved. A comparative analysis between head (H-PDAC) and body-tail (BT-PDAC) tumors was performed using uni- and multivariable models. The accuracy of the eighth AJCC staging system was analyzed using C-statistics. RESULTS: Among 1466 patients, 264 (18%) had BT-PDAC, which displayed greater tumor size but significantly lower rates of perineural invasion and G3/4 grading. Furthermore, BT-PDAC was associated with a lower frequency of nodal involvement and a greater representation of earlier stages. The recurrence-free survival and disease-specific survival times were longer for BT-PDAC (16 vs 14 months [p = 0.020] and 33 vs 26 months [p = 0.026], respectively), but tumor location was not an independent predictor of recurrence or survival in the multivariable analyses. The recurrence patterns did not differ. Certain prognostic factors (i.e., CA 19.9, grading, R-status, and adjuvant treatment) were common, whereas others were site-specific (i.e., preoperative pain, diabetes, and multivisceral resection). The performances of the AJCC staging system were similar (C-statistics of 0.573 for H-PDAC and 0.597 for BT-PDAC, respectively). CONCLUSIONS: Despite differences in pathologic profile found to be in favor of BT-PDAC, tumor location was not an independent predictor of recurrence or survival after pancreatectomy. An array of site-specific prognostic factors was identified, but the AJCC staging system displayed similar prognostic power regardless of primary tumor location.

doi: https://doi.org/10.1245/s10434-020-08354-4

- Pancreatic Neuroendocrine Neoplasms: Landscape and Horizon

Archives of pathology & laboratory medicine 2020 Apr;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32298138

CONTEXT.—: Since the initial description of pancreatic endocrine physiology and the recognition of islet cell tumors in the 1800s, there have been noteworthy advances in the pathobiology of pancreatic neuroendocrine neoplasms (PanNENs), and definition of the important distinction between well-differentiated neuroendocrine tumor (PanNET) and poorly differentiated neuroendocrine carcinoma (PanNEC). The evolving knowledge has resulted in a continuous update in terminology, classification, and grading system for this group of neoplasms. Pancreatic neuroendocrine tumors associated with hereditary conditions have been linked to unique molecular and genetic events, and sporadic PanNETs have specific gene signatures. Based on accumulative experience and knowledge, therapeutic strategies have been defined for this group of neoplasms. OBJECTIVE.—: To review the evolution and description of the pathologic-genomic evolution of PanNENs, and to facilitate accurate pathologic interpretation for the corresponding clinical management. DATA SOURCES.—: Literature review of published studies and author’s own work. CONCLUSIONS.—: Evolving experience and knowledge have established subtypes of pancreatic neuroendocrine neoplasms, based on their genotype and phenotype. Accurate pathologic interpretation of the specific neoplasm has significant implications for therapy and prognosis.

doi: https://doi.org/10.5858/arpa.2019-0654-RA

- How does intestinal-type intraductal papillary mucinous neoplasm emerge? CDX2 plays a critical role in the process of intestinal differentiation and progression

Virchows Archiv : an international journal of pathology 2020 Jul;477(1):21-31

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32291497

Intestinal-type intraductal papillary mucinous neoplasm (IPMN) of the pancreas is clinicopathologically distinctive. Our research aimed to elucidate the molecular mechanism of the development and progression of the intestinal-type IPMN. In 60 intestinal-type IPMN specimens, histological transitions from gastric-type epithelia to intestinal-type epithelia were observed in 48 cases (80%). CDX2/MUC2/alcian blue triple staining indicated that CDX2 appeared to precede MUC2 expression and subsequent alcian blue-positive mucin production. Expression of p21 and Ki-67 seemed to be accelerated by CDX2 expression (p = 6.02e-13 and p = 3.1e-09, respectively). p21/Ki-67 double staining revealed that p21 was mostly expressed in differentiated cells in the apex of papillae, while Ki-67 was expressed in proliferative cells in the base of papillae. This clear cellular arrangement seemed to break down with the progression of atypical grade and development of invasion (p = 0.00197). Intestinal-type IPMNs harbored frequent GNAS mutations (100%, 25/25) and RNF43 mutations (57%, 8/14) and shared identical GNAS and KRAS mutations with concurrent gastric-type IPMNs or incipient gastric-type neoplasia (100%, 25/25). RNF43 mutations showed emerging or being selected in intestinal-type neoplasms along with ß-catenin aberration. Activation of protein kinase A and extracellular-regulated kinase was observed in CDX2-positive intestinal-type neoplasm. These results suggest that gastric-type epithelia that acquire GNAS mutations together with induction of intrinsic CDX2 expression may evolve with clonal selection and additional molecular aberrations including RNF43 and ß-catenin into intestinal-type IPMNs, which may further progress with complex villous growth due to disoriented cell cycle regulation, acceleration of atypical grade, and advance to show an invasive phenotype.

doi: https://doi.org/10.1007/s00428-020-02806-8

- miR-375 Inhibits Autophagy and Further Promotes Inflammation and Apoptosis of Acinar Cells by Targeting ATG7

Pancreas 2020 04;49(4):543-551

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32282768

OBJECTIVES: MicroRNAs have been considered to be closely related with the development of severe acute pancreatitis (SAP), and microRNA-375 (miR-375) was believed to be a marker of SAP. We aim to investigate the role of miR-375 in regulating SP. METHODS: Cerulein and lipopolysaccharide were used to establish the models of SAP. AR42J cell line was chosen for study in vitro. Flow cytometry was applied for assessing apoptosis. The contents of inflammatory factors were detected with related enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction assays. Hematoxylin and eosin staining was applied to observe the pathological changes of pancreatic tissues. Immunohistochemistry analysis was conducted for investigating the expression of light chain 3. RESULTS: The level of miR-375 in pancreatitis tissues and cell lines was upregulated. Overexpression of miR-375 promoted inflammation and the apoptosis of acinar cells through inhibiting autophagy. The binding site between miR-375 and ATG7 was identified, and miR-375 could directly regulate the ATG7. microRNA-375 suppressed autophagy and promoted inflammation and the apoptosis of acinar cells via targeting ATG7. CONCLUSIONS: We proved that miR-375 could inhibit autophagy and promote inflammation and the apoptosis of acinar cells through regulating ATG7. This study first proves that miR-375 modulates the development of SAP through targeting ATG7.

doi: https://doi.org/10.1097/MPA.0000000000001536

- Alteration of Transforming Growth Factor �� Signaling Pathway Predicts Worse Prognosis in Pancreatic Ductal Adenocarcinoma

Pancreas 2020 04;49(4):534-542

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32282767

OBJECTIVES: Transforming growth factor β (TGF-β) signaling pathway is one of the core pathways in pancreatic ductal adenocarcinoma (PDAC). Prognostic value of TGF-β pathway genes as a functionally related group in PDAC is rarely studied. METHODS: Seventy-two PDAC patients who underwent surgery between November 30, 2015, and September 13, 2017, in West China Hospital, Sichuan University, were identified and included in this study. Whole-exome sequencing or targeted next-generation sequencing was performed with tumor tissue. Clinicopathologic characteristics and survival data were retrospectively collected and analyzed. RESULTS: Genetic alterations were detected in 71 patients (98.6%). Although 1 patient (1.4%) had one genetic alteration, 33 patients (45.8%) had 2 to 4 alterations and 37 patients (51.4%) had 5 or more alterations. Twenty-five patients with TGF-β pathway alteration were identified as TGF-βm+ group. Other 47 patients were TGF-βm- group. Mutation of TGF-β pathway was independently associated with inferior survival (hazard ratio, 2.22, 95% confidence interval, 1.05-4.70, P = 0.04), especially in patients accepting radical surgery (hazard ratio, 3.25, 95% confidence interval, 1.01-10.49, P = 0.04). CONCLUSIONS: Inferior prognosis was observed in PDACs with mutations of TGF-β pathway. Genomic information could help screen out patients at risk after surgery, and adjuvant therapy might benefit this subgroup of PDACs.

doi: https://doi.org/10.1097/MPA.0000000000001522

- Aberration of ARID1A Is Associated With the Tumorigenesis and Prognosis of Sporadic Nonfunctional Pancreatic Neuroendocrine Tumors

Pancreas 2020 04;49(4):514-523

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32282764

OBJECTIVE: The genetic aberrations that underlie chromatin remodeling in sporadic nonfunctional pancreatic neuroendocrine tumors (NF-pNETs) remain largely unknown. Here, we investigated the dysregulation of the switch/sucrose nonfermentable (SWI/SNF) component ARID1A and its correlation with clinicopathological features and prognosis. METHODS: We sequenced the exomes of sporadic NF-pNETs. Quantitative real-time polymerase chain reaction and immunohistochemistry were used to determine messenger RNA level and protein expression. RESULTS: The sporadic NF-pNETs harbored 264 somatic mutations in 228 different genes, most commonly affecting the SWI/SNF components ARID1B (57.1%) and ARID1A (42.9%). The expression of ARID1A was remarkably downregulated in NF-pNETs and corresponding liver metastases compared with that in normal pancreatic islet tissue. Reduced expression of ARID1A was associated with malignant clinicopathological features (P < 0.05). The loss of ARID1A was related to a high Ki-67 index (P < 0.05). Patients with ARID1A-negative expression had a significantly worse overall survival rate than those with ARID1A-positive expression (P < 0.05). The ARID1A status was an independent predictor of overall survival, and a nomogram integrating ARID1A with clinicopathological features was proposed. CONCLUSIONS: The loss of SWI/SNF components ARID1A may be associated with malignant behaviors and an unfavorable prognosis. Aberrations of ARID1A may contribute to tumorigenesis and metastasis in sporadic NF-pNETs.

doi: https://doi.org/10.1097/MPA.0000000000001535

- Roles of Autophagy and Pancreatic Secretory Trypsin Inhibitor in Trypsinogen Activation in Acute Pancreatitis

Pancreas 2020 04;49(4):493-497

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32282761

The focus of the review is on roles of autophagy and pancreatic secretory trypsin inhibitor (PSTI), an endogenous trypsin inhibitor, in trypsinogen activation in acute pancreatitis. Acute pancreatitis is a disease in which tissues in and around the pancreas are autodigested by pancreatic digestive enzymes. This reaction is triggered by the intrapancreatic activation of trypsinogen. Autophagy causes trypsinogen and cathepsin B, a trypsinogen activator, to colocalize within the autolysosomes. Consequently, if the resultant trypsin activity exceeds the inhibitory activity of PSTI, the pancreatic digestive enzymes are activated, and they cause autodigestion of the acinar cells. Thus, autophagy and PSTI play important roles in the development and suppression of acute pancreatitis, respectively.

doi: https://doi.org/10.1097/MPA.0000000000001519

- DNA flow cytometric analysis of paraffin-embedded tissue for the diagnosis of malignancy in bile duct biopsies

Human pathology 2020 May;99():80-87

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32272125

Differentiation of reactive versus neoplastic epithelial changes can be challenging in bile duct biopsies. The samples are often scant, distorted, and mixed with significant inflammation, ulceration, and/or debris. Histological confirmation of malignancy is often required before the initiation of surgical therapy, and an erroneous diagnosis of malignancy can lead to unnecessary clinical management. Aneuploidy assessment by DNA flow cytometry was performed on formalin-fixed paraffin-embedded (FFPE) tissue from 63 bile duct biopsies: 10 with a malignant diagnosis (7 with adenocarcinoma and 3 with at least high-grade dysplasia [HGD]); 3 with an atypical diagnosis showing rare atypical glands/cells, concerning but not definite for malignancy; 28 likely reactive biopsies with acute/chronic inflammation, ulceration, and/or mild nuclear atypia; and 22 additional benign biopsies without significant inflammation, ulceration, or nuclear atypia. Aneuploidy was detected in 7 (70%) of the 10 biopsies with definite neoplasia (5 of 7 adenocarcinoma cases and 2 of 3 at least HGD cases), all 3 (100%) atypical biopsies, and none of the 50 benign biopsies. All 3 atypical cases with aneuploidy were subsequently found to have adenocarcinoma (n = 2) or HGD (n = 1). Among the 2 cases of at least HGD with aneuploidy, 1 case developed adenocarcinoma, but no follow-up information was available in the other case. The remaining 1 case of at least HGD, despite having normal DNA content, was found to have adenocarcinoma on follow-up. None of the 50 benign cases (further supported by normal DNA content) developed adenocarcinoma within a mean follow-up time of 37 months (range: 0-282 months). The estimated sensitivity of aneuploidy as a diagnostic marker of malignancy (adenocarcinoma and HGD) was 70%, with the specificity of 100%, positive predictive value of 100%, and negative predictive value of 94%. In conclusion, DNA flow cytometry using FFPE tissue from bile duct biopsies demonstrates a high rate of aneuploidy (70%) in malignant cases and normal DNA content in all benign biopsies. Although the sample size is small, the results indicate that this assay can be potentially useful in challenging atypical cases, where morphological evaluation is limited by scarcity of atypical glands/cells, inflammation, and/or ulceration.

doi: https://doi.org/10.1016/j.humpath.2020.04.002

- A 15-Gene Immune, Stromal, and Proliferation Gene Signature that Significantly Associates with Poor Survival in Patients with Pancreatic Ductal Adenocarcinoma

Clinical cancer research : an official journal of the American Association for Cancer Research 2020 Mar;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32234757

PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with dismal survival rates. Tumor microenvironment (TME), comprising of immune cells and cancer-associated fibroblasts, plays a key role in driving poor prognosis and resistance to chemotherapy. Herein, we aimed to identify a TME-associated, risk-stratification gene biomarker signature in PDAC. EXPERIMENTAL DESIGN: The initial biomarker discovery was performed in The Cancer Genome Atlas (TCGA, n = 163) transcriptomic data. This was followed by independent validation of the gene signature in the International Cancer Genome Consortium (ICGC, n = 95), E-MTAB-6134 (n = 288), and GSE71729 (n = 123) datasets for predicting overall survival (OS), and for its ability to detect poor molecular subtypes. Clinical validation and nomogram establishment was undertaken by performing multivariate Cox regression analysis. RESULTS: Our biomarker discovery effort identified a 15-gene immune, stromal, and proliferation (ISP) gene signature that significantly associated with poor OS [HR, 3.90; 95% confidence interval (CI), 2.36-6.41; P < 0.0001]. This signature also robustly predicted survival in three independent validation cohorts ICGC [HR, 2.63 (1.56-4.41); P < 0.0001], E-MTAB-6134 [HR, 1.53 (1.14-2.04); P = 0.004], and GSE71729 [HR, 2.33 (1.49-3.63); P < 0.0001]. Interestingly, the ISP signature also permitted identification of poor molecular PDAC subtypes with excellent accuracy in all four cohorts; TCGA (AUC = 0.94), ICGC (AUC = 0.91), E-MTAB-6134 (AUC = 0.80), and GSE71729 (AUC = 0.83). The ISP-derived high-risk patients exhibited significantly poor OS in a clinical validation cohort [n = 119; HR, 2.62 (1.50-4.56); P = 0.0004]. A nomogram was established which included the ISP, CA19-9, and T- and N-stage for eventual clinical translation. CONCLUSIONS: We report a novel gene signature for risk-stratification and robust identification of patients with PDAC with poor molecular subtypes.

doi: https://doi.org/10.1158/1078-0432.CCR-19-4044

- Expression Patterns and Prognostic Value of DNA Damage Repair Proteins in Resected Pancreatic Neuroendocrine Neoplasms

Annals of surgery 2020 Mar;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32209898

OBJECTIVE: This study aimed to examine the expression profiles and prognostic value of multiple DDR proteins in resected PanNENs. BACKGROUND: DDR proteins play important roles in various cancers, including pancreatic ductal adenocarcinoma. However, the expression patterns and prognostic value of DDR proteins in PanNENs remain unclear. METHODS: This retrospective analysis included PanNEN patients who underwent resection at the Fudan University Shanghai Cancer Center from 2012 to 2018. Immunohistochemical staining was performed for 12 DDR proteins in tissue microarrays. The associations of DDR protein expression and clinicopathological features with recurrence-free survival (RFS) were examined via a Cox regression model and random survival forest. A recurrence signature was constructed using recursive partitioning analysis. RESULTS: In total, 131 PanNEN patients were included, with 32 (24.4%) cases of recurrence. Among the 12 DDR proteins, low checkpoint kinase 2 (CHK2) expression (P = 0.020) and loss of ataxia-telangiectasia-mutated (ATM) (P = 0.0007) significantly correlated with recurrence. Multivariable Cox regression analysis identified tumor size ≥3 cm, lymph node (LN) metastasis, high tumor grade, low CHK2 expression, and ATM loss as independent risk factors for recurrence. A recurrence signature was established based on the importance of recurrence-specific risk factors; patients with the LNnegTumorSize<3cm signature had a 5-year RFS rate of 96.8%, whereas patients with the LNposCHK2low signature had the worst 5-year RFS rate (0%). Discrimination (concordance index: 0.770) and calibration plots indicated that the recurrence signature had a good ability to identify patients at risk for recurrence. CONCLUSIONS: By analyzing large-scale tissue microarrays of PanNENs, we evaluated 12 DDR protein expression profiles. We developed a recurrence signature that can identify distinct subpopulations according to RFS, which may help refine individual follow-up.

doi: https://doi.org/10.1097/SLA.0000000000003884

- Detection of Circulating Tumor DNA in Patients with Pancreatic Cancer Using Digital Next-Generation Sequencing

The Journal of molecular diagnostics : JMD 2020 Jun;22(6):748-756

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32205290

Circulating tumor DNA (ctDNA) measurements can be used to estimate tumor burden, but avoiding false-positive results is challenging. Herein, digital next-generation sequencing (NGS) is evaluated as a ctDNA detection method. Plasma KRAS and GNAS hotspot mutation levels were measured in 140 subjects, including 67 with pancreatic ductal adenocarcinoma and 73 healthy and disease controls. To limit chemical modifications of DNA that yield false-positive mutation calls, plasma DNA was enzymatically pretreated, after which DNA was aliquoted for digital detection of mutations (up to 384 aliquots/sample) by PCR and NGS. A digital NGS score of two SDs above the mean in controls was considered positive. Thirty-seven percent of patients with pancreatic cancer, including 31% of patients with stages I/II disease, had positive KRAS codon 12 ctDNA scores; only one patient had a positive GNAS mutation score. Two disease control patients had positive ctDNA scores. Low-normal-range digital NGS scores at mutation hotspots were found at similar levels in healthy and disease controls, usually at sites of cytosine deamination, and were likely the result of chemical modification of plasma DNA and NGS error rather than true mutations. Digital NGS detects mutated ctDNA in patients with pancreatic cancer with similar yield to other methods. Detection of low-level, true-positive ctDNA is limited by frequent low-level detection of false-positive mutation calls in plasma DNA from controls.

doi: https://doi.org/10.1016/j.jmoldx.2020.02.010

- Validation of the T category for distal cholangiocarcinoma: Measuring the depth of invasion is complex but correlates with survival

Annals of diagnostic pathology 2020 Mar;46():151489

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32169826

According to the current 8th edition of the American Joint Committee of Cancer (AJCC), the T category of distal cholangiocarcinomas is classified based on the depth of invasion (DOI) (T1, < 5 mm; T2, between 5 and 12 mm; T3, > 12 mm). In consideration of the discrepancies between previous studies about the prognostic significance, we aimed to validate the current AJCC T staging system of distal cholangiocarcinomas. DOI was measured using three different methods: DOI1, DOI2, and DOI3. DOI1 was defined and stratified according to the AJCC 8th edition. DOI2 was measured as the distance from an imaginary curved line approximated along the distorted mucosal surface to the deepest invasive tumor cells. DOI3 was defined as the total tumor thickness. DOI2 and DOI3 were also divided into three categories using the same cut-off points as in the AJCC 8th edition. We compared these three DOI methods to the AJCC 7th edition as well. In contrast with the AJCC 7th edition, all three groups showed a correlation with patients’ overall survival. Above all, the DOI2 group demonstrated the best significance in multivariate analysis. However, when the C indices were compared between these groups, differential significance proved to be negligible (DOI1 vs DOI2, p = 0.915; DOI2 vs DOI3, p = 0.057). Therefore, the measurement of DOI does not need to be rigorously and stringently performed. In conclusion, we showed that the current T classification system better correlates with the overall survival of patients with distal cholangiocarcinomas than the previous system.

doi: https://doi.org/10.1016/j.anndiagpath.2020.151489

- GATA6 Expression Distinguishes Classical and Basal-like Subtypes in Advanced Pancreatic Cancer

Clinical cancer research : an official journal of the American Association for Cancer Research 2020 Mar;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32156747

PURPOSE: To determine the impact of basal-like and classical subtypes in advanced pancreatic ductal adenocarcinoma (PDAC) and to explore GATA6 expression as a surrogate biomarker. EXPERIMENTAL DESIGN: Within the COMPASS trial, patients proceeding to chemotherapy for advanced PDAC undergo tumor biopsy for RNA-sequencing (RNA-seq). Overall response rate (ORR) and overall survival (OS) were stratified by subtypes and according to chemotherapy received. Correlation of GATA6 with the subtypes using gene expression profiling, in situ hybridization (ISH) was explored. RESULTS: Between December 2015 and May 2019, 195 patients (95%) had enough tissue for RNA-seq; 39 (20%) were classified as basal-like and 156 (80%) as classical. RECIST response data were available for 157 patients; 29 basal-like and 128 classical where the ORR was 10% versus 33%, respectively (P = 0.02). In patients with basal-like tumors treated with modified FOLFIRINOX (n = 22), the progression rate was 60% compared with 15% in classical PDAC (P = 0.0002). Median OS in the intention-to-treat population (n = 195) was 9.3 months for classical versus 5.9 months for basal-like PDAC (HR, 0.47; 95% confidence interval, 0.32-0.69; P = 0.0001). GATA6 expression by RNA-seq highly correlated with the classifier (P < 0.001) and ISH predicted the subtypes with sensitivity of 89% and specificity of 83%. In a multivariate analysis, GATA6 expression was prognostic (P = 0.02). In exploratory analyses, basal-like tumors, could be identified by keratin 5, were more hypoxic and enriched for a T-cell-inflamed gene expression signature. CONCLUSIONS: The basal-like subtype is chemoresistant and can be distinguished from classical PDAC by GATA6 expression.

doi: https://doi.org/10.1158/1078-0432.CCR-19-3724

- Validation and modification of staging Systems for Poorly Differentiated Pancreatic Neuroendocrine Carcinoma

BMC cancer 2020 Mar;20(1):188

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32138704

BACKGROUND: The American Joint Committee on Cancer (AJCC) and the European Neuroendocrine Tumor Society (ENETS) staging classifications are two broadly used systems for pancreatic neuroendocrine tumors. This study aims to identify the most accurate and useful tumor-node-metastasis (TNM) staging system for poorly differentiated pancreatic neuroendocrine carcinomas (pNECs). METHODS: An analysis was performed to evaluate the application of the ENETS, 7th edition (7th) AJCC and 8th edition (8th) AJCC staging classifications using the Surveillance, Epidemiology, and End Results (SEER) registry (N = 568 patients), and a modified system based on the analysis of the 7th AJCC classification was proposed. RESULTS: In multivariable analyses, only the 7th AJCC staging system allocated patients into four different risk groups, although there was no significant difference. We modified the staging classification by maintaining the T and M definitions of the 7th AJCC staging and adopting new staging definitions. An increased hazard ratio (HR) of death was also observed from class I to class IV for the modified 7th (m7th) staging system (compared with stage I disease; HR for stage II =1.23, 95% confidence interval (CI) = 0.73-2.06, P = 0.44; HR for stage III =2.20, 95% CI =1.06-4.56, P = 0.03; HR for stage IV =4.95, 95% CI =3.20-7.65, P < 0.001). The concordance index (C-index) was higher for local disease with the m7th AJCC staging system than with the 7th AJCC staging system. CONCLUSIONS: The m7th AJCC staging system for pNECs proposed in this study provides improvements and may be assessed for potential adoption in the next edition.

doi: https://doi.org/10.1186/s12885-020-6634-9

- Global trends in intrahepatic and extrahepatic cholangiocarcinoma incidence from 1993 to 2012

Cancer 2020 Jun;126(11):2666-2678

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32129902

BACKGROUND: Intrahepatic cholangiocarcinomas (ICCs) and extrahepatic cholangiocarcinomas (ECCs) are highly lethal bile duct tumors. Their incidence can be difficult to estimate because of changes in cancer coding over time. No studies to date have examined their global incidence and trends with high-quality topography- and histology-specific cancer registry data. Therefore, this study examined ICC and ECC incidence with the Cancer Incidence in Five Continents Plus database. METHODS: Regional and national cancer registry data were used to estimate age-standardized incidence rates (ASRs) per 100,000 person-years, 95% confidence intervals, and average annual percent changes (AAPCs) for ICC in 38 countries and for ECC in 33 countries from 1993 to 2012. ICC and ECC trends were tabulated and plotted by country. Rates versus birth cohort by age were plotted, and an age-period-cohort analysis was performed to assess age and cohort incidence rate ratios. RESULTS: The highest rates of ICC and ECC were in Asia, specifically South Korea (ASR for ICC, 2.80; ASR for ECC, 2.24), Thailand (ASR for ICC, 2.19; ASR for ECC, 0.71), and Japan (ASR for ICC, 0.95; ASR for ECC, 0.83). Between 1993 and 2012, incidence rates of both ICC and ECC increased in most countries. The largest ASR increases over the study period occurred in Latvia (AAPC, 20.1%) and China (AAPC, 11.1%) for ICC and in Thailand (AAPC, 8.8%) and Colombia (AAPC, 8.5%) for ECC. CONCLUSIONS: In the 20 years examined, ICC and ECC incidence increased in the majority of countries worldwide. ICC and ECC incidence may continue to increase because of metabolic and infectious etiologic factors. Efforts to further elucidate risk factors contributing to these increases in incidence are warranted.

doi: https://doi.org/10.1002/cncr.32803

- INSM1 Is a Highly Specific Marker of Neuroendocrine Differentiation in Primary Neoplasms of the Gastrointestinal Tract, Appendix, and Pancreas

American journal of clinical pathology 2020 May;153(6):811-820

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32128564

OBJECTIVES: INSM1 has been described as a sensitive and specific neuroendocrine marker. This study aims to compare INSM1 with traditional neuroendocrine markers in gastrointestinal neuroendocrine neoplasms. METHODS: Retrospective review (2008-2018) was used to retrieve paraffin-embedded tissue from 110 gastrointestinal neuroendocrine neoplasms and controls that was subsequently stained with INSM1, synaptophysin, chromogranin, CD56, and Ki-67. RESULTS: INSM1 was positive in 16 of 17 (94.1%) gastric, 17 of 18 (94.4%) pancreatic, 13 of 18 (72.2%) small bowel, 17 of 21 (81.0%) colonic, and 26 of 36 (72.2%) appendiceal tumors. INSM1 was positive in 58 of 70 (82.9%) well-differentiated neuroendocrine tumors, 17 of 20 (85.0%) poorly differentiated neuroendocrine carcinomas, 8 of 11 (72.7%) low-grade goblet cell adenocarcinomas (grade 1), and 6 of 9 (66.7%) high-grade goblet cell adenocarcinomas (grade 2/3). INSM1 sensitivity for neuroendocrine neoplasms (80.9%) was less than that of synaptophysin (99.1%), chromogranin (88%), and CD56 (95.3%); specificity was higher (95.7% vs 86.0%, 87.3%, and 86.0%, respectively). CONCLUSIONS: INSM1 is a useful marker of neuroendocrine differentiation in gastrointestinal neuroendocrine and mixed neuroendocrine neoplasms. Compared with traditional neuroendocrine markers, INSM1 is less sensitive but more specific.

doi: https://doi.org/10.1093/ajcp/aqaa014

- Global, regional and national burden of pancreatic cancer, 1990 to 2017: Results from the Global Burden of Disease Study 2017

Pancreatology : official journal of the International Association of Pancreatology (IAP) … [et al.] 2020 Apr;20(3):462-469

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32113937

BACKGROUND: The global burden of pancreatic cancer (PCa) continues to grow. Detailed data on PCa epidemiology are essential for policy-making and appropriate healthcare resource allocation. METHODS: Estimates of incidence, death and disability-adjusted life years (DALYs) of PCa from 1990 to 2017 were collected from the Global Burden of Disease Study 2017. Decomposition analysis was conducted to detect the contributing factors related to PCa incidence variation. The estimated annual percentage change (EAPC) was calculated to quantify the PCa epidemiology trends over a specified interval. RESULTS: Globally, the incidence of PCa cases increased by 129.1% to 447 664 664 (95% uncertainty interval (UI) 438 597-456 295), death increased by 125.2% to 441 082 082 (95% UI 448 960-432 833), and DALYs increased by 107.3% to 9 080 004 (95% UI 8 894 128-9 256 346) between 1990 and 2017. Relatively higher sociodemographic index (SDI) regions were observed with greater incidences, more deaths and a greater number of DALYs of PCa, but relatively lower SDI regions experienced a sharply increasing trend in these measures. Decomposition analysis indicated that the global increase in PCa incidence was driven by the aging population from 2007 to 2017, especially in higher SDI regions. In addition, a significant negative correlation was found between EAPC and ASIR (in 1990) (r = -0.56, P < 0.001). CONCLUSIONS: PCa remains a major public health burden globally. The unfavorable trend in PCa suggesting that further study for prevention should be conducted to forestall the increase in pancreatic cancer.

doi: https://doi.org/10.1016/j.pan.2020.02.011

- TRAIL receptors are differentially regulated and clinically significant in gallbladder cancer

Pathology 2020 Apr;52(3):348-358

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32111400

Deregulation of the receptors of TNF-related apoptosis inducing ligand (TRAIL) has been reported in various cancers. In an effort to define the role of these receptors we profiled their expression in gallbladder cancer (GBC) and explored their clinical significance. Expression of TRAIL receptors’ mRNA in GBC was analysed through reverse transcriptase polymerase chain reaction (RT-PCR), and protein through western blotting, immunohistochemistry and enzyme-linked immunosorbent assay (ELISA). mRNA data show frequent higher expression of TRAIL receptors in GBC samples. Death receptors DR4 and DR5 showed significant negative correlation with tumour stage, T stage and tumour grade; DcR1 transcript showed positive correlation with tumour stage, N stage, M stage and tumour grade. Similarly, IHC showed frequent positive staining for DR4, DR5 and DcR1in GBC samples. Cytoplasmic and nuclear DR4 protein showed negative correlation with T stage and tumour grade, whereas cytoplasmic DcR1 protein showed positive correlation with tumour stage and N stage. Nuclear DcR1 showed positive correlation with N stage. ELISA results showed significantly higher expression of secretory DcR1 in GBC patients. Kaplan-Meier analysis demonstrated significantly decreased mean survival of patients with positive staining of cytoplasmic DcR1. High level of death receptors identified the patients with early gallbladder cancer, whereas high DcR1 expression served as a prognostic factor for poor outcome.

doi: https://doi.org/10.1016/j.pathol.2019.12.001

- MMR Deficiency is Homogeneous in Pancreatic Carcinoma and Associated with High Density of Cd8-Positive Lymphocytes

Annals of surgical oncology 2020 Feb;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32108923

BACKGROUND: Microsatellite instability (MSI) has emerged as a predictive biomarker for immune checkpoint inhibitor therapy. Cancer heterogeneity represents a potential obstacle for the analysis of predicitive biomarkers. MSI has been reported in pancreatic cancer, but data on the possible extent of intratumoral heterogeneity are lacking. METHODS: To study MSI heterogeneity in pancreatic cancer, a tissue microarray (TMA) comprising 597 tumors was screened by immunohistochemistry with antibodies for the mismatch repair (MMR) proteins MLH1, PMS2, MSH2, and MSH6. RESULTS: In six suspicious cases, large section immunohistochemistry and microsatellite analysis (Bethesda panel) resulted in the identification of 4 (0.8%) validated MSI cases out of 480 interpretable pancreatic ductal adenocarcinomas. MSI was absent in 55 adenocarcinomas of the ampulla of Vater and 7 acinar cell carcinomas. MMR deficiency always involved MSH6 loss, in three cases with additional loss of MSH2 expression. Three cancers were MSI-high and one case with isolated MSH6 loss was MSS in PCR analysis. The analysis of 44 cancer-containing tumor blocks revealed that the loss of MMR protein expression was always homogeneous in affected tumors. Automated digital image analysis of CD8 immunostaining demonstrated markedly higher CD8 + tumor infiltrating lymphocytes in tumors with (mean = 685, median = 626) than without (mean = 227; median = 124) MMR deficiency (p < 0.0001), suggesting a role of MSI for immune response. CONCLUSIONS: Our data suggest that MSI occurs early in a small subset of ductal adenocarcinomas of the pancreas and that immunohistochemical MMR analysis on limited biopsy or cytology material may be sufficient to estimate MMR status of the entire cancer mass.

doi: https://doi.org/10.1245/s10434-020-08209-y

- Intraductal papillary neoplasms of the bile duct consist of two distinct types specifically associated with clinicopathological features and molecular phenotypes

The Journal of pathology 2020 May;251(1):38-48

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32100878

Intraductal papillary neoplasm of the bile duct (IPNB) is a grossly visible papillary biliary neoplasm with morphological variations and occasional invasion. Recently a new classification of IPNB into type 1 and type 2 was proposed in which the type 1 IPNBs consist of fine papillary neoplastic glands and the type 2 IPNBs consist of complex branching glands, seldom with foci of solid-tubular components. However, clinicopathological and molecular characteristics of these types of IPNBs are yet to be identified. We aimed to uncover clinicopathological and molecular characteristics of the types of IPNBs. Thirty-six IPNBs were studied retrospectively. Clinicopathological features as well as molecular alterations of 31 genes were evaluated by means of targeted next-generation sequencing and immunohistochemical examination of expression of mucin and cancer-associated molecules. The 36 IPNBs were classified into 22 of type 1 and 14 of type 2. The type 1 IPNBs were associated with a non-invasive phenotype, intestinal and oncocytic subtypes, development in the intrahepatic bile duct, overt mucin production, and a relatively good prognosis. The type 2 IPNBs were associated with an invasive phenotype, the pancreatobiliary subtype, development within the extrahepatic bile duct, and worse prognosis compared with the type 1 IPNBs. In the molecular analysis, recurrent mutations were found in TP53 (34.3%), KRAS (31.4%), STK11 (25.7%), CTNNB1 (17.1%), APC (14.3%), SMAD4 (14.3%), GNAS (11.4%), PBRM1 (11.4%), ELF3 (8.6%), KMT2C (8.6%), NF1 (8.6%), PIK3CA (8.6%), ARID1A (5.7%), ARID2 (5.7%), BAP1 (5.7%), BRAF (5.7%), EPHA6 (5.7%), ERBB2 (5.7%), ERBB3 (5.7%), KMT2D (5.7%), and RNF43 (5.7%). Mutations in KRAS and GNAS were enriched in the type 1 IPNBs, whereas mutations in TP53, SMAD4, and KMT2C were enriched in the type 2 IPNBs. These results indicate that IPNBs consist of two distinct types of neoplasms specifically associated with clinicopathological features and molecular phenotypes. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

doi: https://doi.org/10.1002/path.5398

- Tumor-insular Complex in Neoadjuvant Treated Pancreatic Ductal Adenocarcinoma Is Associated With Higher Residual Tumor

The American journal of surgical pathology 2020 Jun;44(6):817-825

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32091434

The tumor microenvironment in pancreatic ductal adenocarcinoma (PDAC) plays a vital role in treatment response, and therefore, patient survival. We and others have observed an intimate association of neoplastic ductal cells with non-neoplastic islet cells, recapitulating the ductoinsular complex. We define this phenomenon as tumor-insular complex (TIC). Herein, we describe the clinicopathologic characteristics of TIC in neoadjuvant treated PDAC cases for the first time. We retrospectively reviewed the pathology of 105 cases of neoadjuvant treated PDAC resected at our institution. TIC was noted in 35 cases (33.3%), the mean tumor bed size was 2.7±1.0 cm, mean percentage of residual tumor 40±28% and mean Residual Tumor Index (RTI) (an index previously established as a prognostic parameter by our group) was 1.1±1.0. TIC was significantly associated with perineural invasion (P=0.001), higher tumor bed size (P=0.007), percentage of residual tumor (P=0.009), RTI (P=0.001), ypT stage (P=0.045), and poor treatment response, grouped by a previously established criteria (P=0.010). Using our prior binary reported prognostic cutoff for RTI of ≤0.35 and >0.35, TIC was associated with a RTI >0.35 (P=0.002). Moreover, patients who did not receive neoadjuvant radiation were associated with a higher frequency of TIC (P=0.003). In this cohort, RTI but not TIC was also shown to be a significant independent prognosticator for recurrence-free survival and overall survival on multivariate analysis. In conclusion, TIC is significantly associated with a more aggressive neoplasm which shows a poor treatment response. Further studies will be needed to better understand the tumor biology of TICs.

doi: https://doi.org/10.1097/PAS.0000000000001454

- Clinical Significance of CBS and CCL21 in Gallbladder Adenocarcinomas and Squamous Cell/Adenosquamous Carcinomas

Applied immunohistochemistry & molecular morphology : AIMM 2020 02;28(2):103-110

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32044878

Gallbladder cancer (GBC) is a rare disease with high mortality. However, no biomarkers for the carcinogenesis, progression, prognosis, and early diagnosis are clinically available. This study investigated the expressions of cystathionine-β-synthase (CBS) and C-C chemokine receptor 7 (CCR7) protein and their clinical and pathologic significances in gallbladder squamous cell/adenosquamous carcinomas (SC/ASC) and adenocarcinomas (AC). CBS and chemokine ligand 21 (CCL21) expression was measured using immunohistochemistry in 69 SC/ASCs and 146 ACs. A significantly high percentage of patients with an age above 45 years, lymph node metastasis, and invasion was observed in the SCs/ASCs compared with ACs (P<0.05). Both AC and SC/ASC patients with positive CBS and CCL21 expression exhibited a high tumor-lymph node-metastasis stage, lymph node metastasis, and invasion compared with patients with negative CBS and CCL21 expression (P<0.05 or P<0.01). SC/ASC patients with positive CBS expression was prone to have a larger tumor size than those with negative expression (P<0.05). Positive CBS and CCL21 expression correlated with poor differentiation and larger tumor size in AC patients. Positive CBS and CCL21 are closely associated with a decreased overall survival in SC/ASC and AC patients (P<0.05 or P<0.01) and were independent factors for a poor-prognosis. Both CBS and CCL21 showed a good overall diagnostic performance for SC/ASC (AUC=0.742 and AUC=0.764, respectively) and AC (AUC=0.734 and AUC=0.718, respectively). In conclusion, positive CBS and CCL21 expression are closely associated with the clinical severity and poor prognosis in GBC, and can be a marker for the diagnosis of AC and SC/ASC type of GBC.

doi: https://doi.org/10.1097/PAI.0000000000000705

- Germline alterations in patients with biliary tract cancers: A spectrum of significant and previously underappreciated findings

Cancer 2020 Jan;126(9):1995-2002

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32012241

BACKGROUND: With limited information on germline mutations in biliary tract cancers, this study performed somatic and germline testing for patients at Memorial Sloan Kettering Cancer Center with known biliary tract carcinoma with the aim of determining the frequency and range of pathogenic germline alterations (PGAs). METHODS: Patients with biliary tract carcinoma were consented for somatic tumor and matched blood testing of up to 468 genes via the Memorial Sloan Kettering Cancer Center Integrated Mutation Profiling of Actionable Cancer Targets next-generation sequencing platform. A germline variant analysis was performed on a panel of up to 88 genes associated with an increased predisposition for cancer. Demographic and diagnostic details were collected. RESULTS: Germline mutations were tested in 131 patients. Intrahepatic cholangiocarcinoma was the most common cancer (63.4%), and it was followed by gallbladder adenocarcinoma (16.8%), extrahepatic cholangiocarcinoma (16%), and otherwise unspecified biliary tract cancer (3.8%). Known and likely PGAs were present in 21 patients (16.0%), with 9.9% harboring a PGA in a high/moderate-penetrance cancer predisposition gene. Among high-penetrance cancer susceptibility genes, PGAs were most commonly observed in BRCA1 and BRCA2 (33.3%), which made up 5.3% of the entire cohort, and they were followed by PALB2, BAP1, and PMS2. Mutations in ATM, MITF, and NBN, moderate-penetrance cancer susceptibility genes, were identified in 1 patient each. There was no observed difference in the types of mutations among the subtypes of biliary tract cancer. CONCLUSIONS: The frequency of PGAs found was comparable to existing data on the prevalence of germline mutations in other solid tumor types with matched tumor analysis. This provides support for the role of the BRCA1/2, ATM, and BAP1 genes in biliary tract cancer susceptibility.

doi: https://doi.org/10.1002/cncr.32740

- Smooth Muscle Distribution Patterns of Choledochal Cysts and Their Implications for Pathogenesis and Postoperative Complications

American journal of clinical pathology 2020 May;153(6):760-771

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=32010932

OBJECTIVES: Histopathologic characteristics of choledochal cysts and their clinical implications have not been previously comprehensively studied. METHODS: Smooth muscle distribution patterns and other histologic findings (inflammation, metaplasia, dysplasia, and heterotopia) in 233 surgically resected choledochal cysts were evaluated. RESULTS: Mean patient age was 23.3 ± 19.8 years, with male:female ratio of 0.3. Most cases were Todani type I (175 cases, 75.1%) or IVa (56 cases, 24.1%). Choledochal cysts with thin scattered/no muscle fiber (175 cases, 75.1%) were the predominant pattern and were associated with more frequent postoperative biliary stricture (P = .031), less frequent pyloric metaplasia (P = .016), and mucosal smooth muscle aggregates (P < .001) compared to cysts with thick muscle bundles. Severe chronic cholangitis (P = .049), pyloric metaplasia (P = .019), mucosal smooth muscle aggregates (P < .001), biliary intraepithelial neoplasia (P = .021), and associated bile duct (P = .021) and gallbladder carcinomas (P = .03) were more common in adults (age >20 years vs ≤20 years), suggesting that chronic irritation in association with developmental anomalies involves tumorigenesis from choledochal cysts. CONCLUSION: Smooth muscle distribution pattern of choledochal cyst may predict postoperative complication, raising clinical implications of smooth muscle patterns in postoperative management of choledochal cysts.

doi: https://doi.org/10.1093/ajcp/aqaa002

- Innervation of the proximal human biliary tree

Virchows Archiv : an international journal of pathology 2020 Jan;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31993770

The autonomic nervous system plays a role in a variety of liver regenerative and metabolic functions, including modulating bile secretion and cholangiocyte and hepatobiliary progenitors of the canals of Hering. However, the nature and location of nerves which link to the proximal biliary tree have remained uncertain. We investigate the anatomic relationship of nerves to the proximal biliary tree including the putative stem/progenitor cell niche of the canal of Hering. Using double immunostaining (fluorescence, histochemistry) to highlight markers of cholangiocytes (biliary-type keratins), nerves (S100, neurofilament protein, PGP9.5, tyrosine hydroxylase), and stellate cells (CRBP-1), we examined sections from normal adult livers from autopsy or surgical resections. There is extensive contact between nerves and interlobular bile ducts, bile ductules, and canals of Hering (CoH). In multiple serial sections from 4 normal livers, biliary-nerve contacts were seen in all of these structures and were more common in the interlobular bile ducts (78/137; 57%) than in the ductules and CoH (95/294; 33%) (p < 0.001). Contacts appear to consist of nerves in juxtaposition to the biliary basement membrane, though crossing through basement membrane to interface directly with cholangiocytes is also present. These nerves are positive for tyrosine hydroxylase and are, thus, predominately adrenergic. Electron microscopy confirms nerves closely approximating ductules. Nerve fiber-hepatic stellate cell juxtaposition is observed but without stellate cell approximation to cholangiocytes. We present novel findings of biliary innervation, perhaps mediated in part, by direct cholangiocyte-nerve interactions. The implications of these findings are protean for studies of neuromodulation of biliary physiology and hepatic stem/progenitor cells.

doi: https://doi.org/10.1007/s00428-020-02761-4

- Luschka Ducts of the Gallbladder in Adults: Case Series Report and Review of the Medical Literature

International journal of surgical pathology 2020 Aug;28(5):482-489

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31983263

Luschka ducts (LD) of the gallbladder (GB) are rare congenital lesions. They are defined as bile ducts that connect directly the hepatic bile duct system to the GB. We aimed to present the characteristics of 55 cases of GB LDs as diagnosed on cholecystectomy specimens. Surgically resected GBs (55) were analyzed for LD morphological features (length, morphological pattern, and epithelial lesions) as well as for immunohistochemical features. The age varied between 24 and 88 years. The gender ratio was 30:25 (female-male). The diagnosis was acute and subacute/chronic cholecystitis (21 and 34 cases, respectively). GB abnormalities of Rokitansky-Aschoff sinus, adenomyoma, septate, and subserosal-liver types were present in 36, 6, 22, and 12 GBs, respectively, while adenocarcinoma was present in 2 GBs. A history of renal cyst, pancreatitis, and colon diverticulosis was observed in 8, 11, and 4 cases, respectively. The LDs were detected at subserosal, resection, or both sites (25, 4, and 26 cases, respectively). The length varied between <1 and 36 mm. Duct-type LDs were observed in 17 cases, complex-type LDs in 5 cases, and mixed-type LDs in 33 cases. Mucosecretion was seen in 12 LDs and cystic dilatation in 8 cases. Epithelial atypia was observed in 2 cases and meganucleoli in 15 cases. Presence of LD-angulation correlated with chronic cholecystitis, while LD-nuclear atypia correlated with acute cholecystitis. In conclusion, LDs may harbor varied aspects, from duct-like or cystic, to nodular, biliary adenoma-like complexes. GB abnormalities of Rokitansky-Aschoff sinus, septa, or subserosal-liver types and extra-GB lesions such as renal cysts, pancreatitis, and colon diverticulosis were associated.

doi: https://doi.org/10.1177/1066896920901334

- Insulinoma-associated protein 1 (INSM1) is a robust marker for identifying and grading pancreatic neuroendocrine tumors

Cancer cytopathology 2020 Apr;128(4):269-277

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31977134

BACKGROUND: Pancreatic neuroendocrine tumor (PNET) is a diagnostic challenge with limited samples in not only identification but grading. Prior studies have shown insulinoma-associated protein 1 (INSM1) to be a robust marker in identifying PNETs from other solid pancreatic tumors on resection specimens. In this study, we investigated the utility of INSM1 not only for identifying PNETs but also for grading in cell blocks (CBs) and surgical resections (SRs). METHODS: A search for PNET cases between 2000 and 2019 identified 55 samples (26 CBs and 29 SRs) that were further separated into high (2 CBs, 3 SRs), intermediate (4 CBs, 7 SRs), and low (20 CBs, 19 SRs) grades based on their final pathology report and Ki-67 level. Immunohistochemical (IHC) staining for INSM1 (C-8, Santa Cruz Biotechnology [1:100]) was performed and quantified using an H score of 0 to 300. Non-PNET solid pancreatic tumors were compared and included acinar cell carcinoma, solid pseudopapillary neoplasm, and ductal adenocarcinoma. RESULTS: All 55 cases of PNET demonstrated nuclear INSM1 staining. The average H scores for INSM1 staining of PNET were 254 and 252 in CB and SR, respectively. The H scores decreased with increasing tumor grade, with low-grade (G1), intermediate-grade (G2), and high-grade (G3) tumors showing average INSM1 H scores of 229 and 253, 266 and 253, and 30 and 33 in both CB and SR, respectively. CONCLUSION: IHC with INSM1 plays a role in identifying and potentially grading PNETs.

doi: https://doi.org/10.1002/cncy.22242

- Microscopic size measurements in post-neoadjuvant therapy resections of pancreatic ductal adenocarcinoma (PDAC) predict patient outcomes

Histopathology 2020 Jul;77(1):144-155

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31965618

AIMS: Pancreatic ductal adenocarcinomas (PDACs) are increasingly being treated with neoadjuvant therapy. However, the American Joint Committee on Cancer (AJCC) 8th edition T staging based on tumour size does not reflect treatment effect, which often results in multiple, small foci of residual tumour in a background of mass-forming fibrosis. Thus, we evaluated the performance of AJCC 8th edition T staging in predicting patient outcomes by the use of a microscopic tumour size measurement method. METHODS AND RESULTS: One hundred and six post-neoadjuvant therapy pancreatectomies were reviewed, and all individual tumour foci were measured. T stages based on gross size with microscopic adjustment (GS) and the largest single microscopic focus size (MFS) were examined in association with clinicopathological variables and patient outcomes. Sixty-three of 106 (59%) were locally advanced; 78% received FOLFIRINOX treatment. The average GS and MFS were 25 mm and 11 mm, respectively; nine cases each were classified as T0, 35 and 85 cases as T1, 42 and 12 cases as T2, and 20 and 0 cases as T3, based on the GS and the MFS, respectively. Higher GS-based and MFS-based T stages were significantly associated with higher tumour regression grade, lymphovascular and perineural invasion, and higher N stage. Furthermore, higher MFS-based T stage was significantly associated with shorter disease-free survival (DFS) (P < 0.001) and shorter overall survival (OS) (P = 0.002). GS was significantly associated with OS (P = 0.046), but not with DFS. CONCLUSIONS: In post-neoadjuvant therapy PDAC resections, MFS-based T staging is superior to GS-based T staging for predicting patient outcomes, suggesting that microscopic measurements have clinical utility beyond the conventional use of GS measurements alone.

doi: https://doi.org/10.1111/his.14067

- Gallbladder and extrahepatic bile duct cancers in the Americas: Incidence and mortality patterns and trends

International journal of cancer 2020 Aug;147(4):978-989

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31922259

Trends in gallbladder cancer incidence and mortality in populations across the Americas can provide insight into shifting epidemiologic patterns and the current and potential impact of preventative and curative programs. Estimates of gallbladder and extrahepatic bile duct cancer incidence and mortality for the year 2018 were extracted from International Agency for Research on Cancer (IARC) GLOBOCAN database for 185 countries. Recorded registry-based incidence from 13 countries was extracted from IARCs Cancer Incidence in Five Continents series and corresponding national deaths from the WHO mortality database. Among females, the highest estimated incidence for gallbladder and extrahepatic bile duct cancer in the Americas were found in Bolivia (21.0 per 100,000), Chile (11.7) and Peru (6.0). In the US, the highest incidence rates were observed among Hispanics (1.8). In the Chilean population, gallbladder cancer rates declined in both females and males between 1998 and 2012. Rates dropped slightly in Canada, Costa Rica, US Whites and Hispanics in Los Angeles. Gallbladder cancer mortality rates also decreased across the studied countries, although rising trends were observed in Colombia and Canada after 2010. Countries within Southern and Central America tended to have a higher proportion of unspecified biliary tract cancers. In public health terms, the decline in gallbladder cancer incidence and mortality rates is encouraging. However, the slight increase in mortality rates during recent years in Colombia and Canada warrant further attention. Higher proportions of unspecified biliary tract cancers (with correspondingly higher mortality rates) suggest more rigorous pathology procedures may be needed after surgery.

doi: https://doi.org/10.1002/ijc.32863

- Long-term outcomes of surgical resection for T1b gallbladder cancer: an institutional evaluation

BMC cancer 2020 Jan;20(1):20

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31907021

BACKGROUND: There is no comprehensive agreement concerning the overall performance of radical resection for T1b gallbladder cancer (GBC). This research focused on addressing whether T1b GBC may spread loco-regionally and whether radical resection is necessary. METHODS: A retrospective analysis was conducted of 1032 patients with GBC who underwent surgical resection at our centre and its affiliated institutions between January 1982 and December 2018. A total of 47 patients with T1b GBC, 29 (62%) of whom underwent simple cholecystectomy and 18 (38%) of whom underwent radical resection with regional lymph node dissection, were enrolled in the study. RESULTS: GBC was diagnosed pre-operatively in 16 patients (34%), whereas 31 patients (66%) had incidental GBC. There was no blood venous or perineural invasion in any patient on histology evaluation, except for lymphatic vessel invasion in a single patient. There were no metastases in any analysed lymph nodes. The open surgical approach was more prevalent among the 18 patients who underwent radical resection (open in all 18 patients) than among the 29 patients who underwent simple cholecystectomy (open in 21; laparoscopic in 8) (P = 0.017). The cumulative 10- and 20-year overall survival rates were 65 and 25%, respectively. The outcome following simple cholecystectomy (10-year overall survival rate of 66%) was akin to that following radical resection (64%, P = 0.618). The cumulative 10- and 20-year disease-specific survival rates were 93 and 93%, respectively. The outcome following simple cholecystectomy (10-year disease-specific survival rate of 100%) was equivalent to that following radical resection (that of 86%, P = 0.151). While age (> 70 years, hazard ratio 5.285, P = 0.003) and gender (female, hazard ratio 0.272, P = 0.007) had a strong effect on patient overall survival, surgical procedure (simple cholecystectomy vs. radical resection) and surgical approach (open vs. laparoscopic) did not. CONCLUSIONS: Most T1b GBCs represent local disease. As pre-operative diagnosis, including tumour penetration of T1b GBC, is difficult, the decision of radical resection is justified. Additional radical resection is not required following simple cholecystectomy provided that the penetration depth is restricted towards the muscular layer and that surgical margins are uninvolved.

doi: https://doi.org/10.1186/s12885-019-6507-2

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PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=

doi: https://doi.org/

- The North American Neuroendocrine Tumor Society Consensus Paper on the Surgical Management of Pancreatic Neuroendocrine Tumors

Pancreas 2020 01;49(1):1-33

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31856076

This manuscript is the result of the North American Neuroendocrine Tumor Society consensus conference on the surgical management of pancreatic neuroendocrine tumors from July 19 to 20, 2018. The group reviewed a series of questions of specific interest to surgeons taking care of patients with pancreatic neuroendocrine tumors, and for each, the available literature was reviewed. What follows are these reviews for each question followed by recommendations of the panel.

doi: https://doi.org/10.1097/MPA.0000000000001454

- Pathologic Evaluation of Endoscopically Resected Non-Ampullary Duodenal Lesions: A Single Center Experience

Turk patoloji dergisi 2020 12;36(2):109-115

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31825518

OBJECTIVE: Endoscopic resections are increasingly being used for superficial gastrointestinal lesions. However, application of these techniques in the duodenum remains challenging, due to the technical difficulties and high complication rates. This study projects a western tertiary center’s experience in the endoscopic treatment and diagnostic workup of 19 cases of non-ampullary duodenal lesions. MATERIAL AND METHOD: Specimens (12 endoscopic mucosal resections, 6 endoscopic submucosal dissections, and one endoscopic full-thickness resection) were processed following a strict protocol (photographed, mapped digitally and submitted totally) for histopathologic examination. Clinicopathologic characteristics, margin status and follow-up information were analyzed. RESULTS: The mean age of the 16 patients was 52 years (range: 22-81). Mean lesion size was 1.4 cm (range: 0.3-3.6 cm) for all cases, 2 cm for endoscopic submucosal dissections and 1.1 cm for endoscopic mucosal resections. Mean number of blocks submitted was 4/case. Seven neuroendocrine tumors, 3 tubulovillous adenomas were diagnosed along with nine benign lesions. For endoscopic submucosal dissections, en-bloc and R0 resection rates were 100% (n=6/6) and 83% (n=5/6); for endoscopic mucosal resections, they were 92% (n=11/12) and 83% (n=10/12), respectively. Only one patient had procedure-related late perforation that was managed endoscopically. No mortality was encountered. CONCLUSION: Duodenal endoscopic resections proved successful, safe and feasible methods in a tertiary center. The pathologist’s role is to designate the accurate diagnosis, related histopathologic parameters and margin status. The gross protocol was found to be essential in evaluating specimen margins and orientation, as well as in size measurement. We recommend following a standardized approach including gross photography and digital mapping when handling these specimens, for both diagnostic and data collection purposes.

doi: https://doi.org/10.5146/tjpath.2019.01474

- Intracholecystic Papillary-Tubular Neoplasms (ICPN) of the Gallbladder: A Short Review of Literature

Applied immunohistochemistry & molecular morphology : AIMM 2020 01;28(1):57-61

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31815746

Increasing use of radiographic studies of the hepatobiliary system has led to a growing diagnostic rate of many asymptomatic polyps of the gallbladder which would have gone undiagnosed otherwise. Neoplastic polyps of the gallbladder are 5% of the total number of polyps of this organ. However, due to their malignant potential, the correct diagnosis and classification become of crucial importance. Lack of unified terminology and reporting criteria have led to a limited body of scientific evidence regarding their classification and management. Therefore in 2012 the novel and unified terminology, Intracholecystic papillary-tubular neoplasm was proposed for these lesions when they measure >1 cm. Smaller lesions are usually of no adverse outcome. Intracholecystic papillary-tubular neoplasms show 5 histologic subcategories: (1) pyloric gland subtype which is the most commonly encountered neoplastic polyp in the gallbladder and has the lowest rate of harboring high-grade dysplasia and invasive carcinoma and it shows diffuse cytoplasmic positivity with MUC6, a specific pyloric marker; (2) biliary subtype which is diffusely positive for MUC1 and has the highest risk of concurrent adenocarcinoma; (3) gastric foveolar subtype which is MUC5AC positive in all the cases. Most of the cases in this category are associated with some extent of high-grade dysplasia; (4) intestinal subtype which is the easiest one to recognize as it mimics tubular adenomas of the gastrointestinal tract and show MUC2 and CDX2 positivity; and (5) oncocytic subtype which is the least common.

doi: https://doi.org/10.1097/PAI.0000000000000711

- Clinicopathologic and Prognostic Significance of Gallbladder and Cystic Duct Invasion in Distal Bile Duct Carcinoma

Archives of pathology & laboratory medicine 2020 Jun;144(6):755-763

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31755778

CONTEXT.—: The roles of the gallbladder and cystic duct (CD) invasions in distal bile duct carcinoma (DBDC) have not been well elucidated. OBJECTIVE.—: To define the characteristics and prognostic significance of gallbladder or CD invasions in patients with DBDC. DESIGN.—: Organ invasion patterns with clinicopathologic features were assessed in 258 resected DBDCs. RESULTS.—: CD invasions (N = 31) were associated with frequent concomitant pancreatic and/or duodenal invasions (23 of 31, 74%) and showed stromal infiltration (16 of 31, 52%) and intraductal cancerization (15 of 31, 48%) patterns. In only 2 cases, invasions with intraductal cancerization were observed in the gallbladder neck. Conversely, all pancreatic (N = 175) and duodenal (83) invasions developed through stromal infiltration. CD invasions were associated with larger tumor size (P = .001), bile duct margin positivity (P = .001), perineural invasions (P = .04), and higher N categories (P = .007). Patients with pancreatic or duodenal invasions had significantly lower survival rates than those without pancreatic (median, 31.0 versus 93.9 months) or duodenal (27.5 versus 56.8 months, P < .001, both) invasions. However, those with gallbladder or CD invasions did not have different survival times (P = .13). Patients with concomitant gallbladder/CD and pancreatic/duodenal invasions demonstrated significantly lower survival rates than those without organ invasions (P < .001). CONCLUSIONS.—: Gallbladder invasions were rare in DBDCs as neck invasions with intraductal cancerization. CD invasions occurred by stromal infiltrations and intraductal cancerization, whereas all pancreatic and duodenal invasions had stromal infiltration patterns. Gallbladder and/or CD invasions did not affect survival rates of patients with DBDC, while pancreatic and duodenal invasions affected survival rates. Therefore, these differences in survival rates may originate from the different invasive patterns of DBDCs.

doi: https://doi.org/10.5858/arpa.2019-0218-OA

- Re-resection in Incidental Gallbladder Cancer: Survival and the Incidence of Residual Disease

Annals of surgical oncology 2020 Apr;27(4):1132-1142

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31741109

BACKGROUND: Re-resection for incidental gallbladder cancer (iGBC) is associated with improved survival but little is known about residual disease (RD) and prognostic factors. In this study, survival after re-resection, RD, and prognostic factors are analyzed. METHODS: Patients with iGBC were identified from the Netherlands Cancer Registry, and pathology reports of re-resected patients were reviewed. Survival and prognostic factors were analyzed. RESULTS: Overall, 463 patients were included; 24% (n = 110) underwent re-resection after a median interval of 66 days. RD was present in 35% of patients and was most frequently found in the lymph nodes (23%). R0 resection was achieved in 93 patients (92%). Median overall survival (OS) of patients without re-resection was 13.7 (95% confidence interval [CI] 11.6-15.6), compared with 52.6 months (95% CI 36.3-68.8) in re-resected patients (p < 0.001). After re-resection, median OS was superior in patients without RD versus patients with RD (not reached vs. 23.1 months; p < 0.001). In patients who underwent re-resection, RD in the liver (hazard ratio [HR] 5.54; p < 0.001) and lymph nodes (HR 2.35; p = 0.005) were the only significant prognostic factors in multivariable analysis. Predictive factors for the presence of RD were pT3 stage (HR 25.3; p = 0.003) and pN1 stage (HR 23.0; p = 0.022). CONCLUSION: Re-resection for iGBC is associated with improved survival but remains infrequently used and is often performed after the optimal timing interval. RD is the only significant prognostic factor for survival after re-resection and can be predicted by pT and pN stages.

doi: https://doi.org/10.1245/s10434-019-08074-4

- Non-neoplastic Polyps of the Gallbladder: A Clinicopathologic Analysis of 447 Cases

The American journal of surgical pathology 2020 Apr;44(4):467-476

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31725469

There is no systematic histopathologic analysis of non-neoplastic polyps in the gallbladder. In this study, in addition to a computer search for cases designated as “polyp,” a systematic review of 2533 consecutive routinely sampled archival and 203 totally submitted prospective cholecystectomies were analyzed for >2 mm polyps (cut-off was based on radiologic sensitivity). A total of 447 non-neoplastic polyps were identified. The frequency was 3% in archival cases and 5% in totally submitted cases. Only 21 (5%) were ≥1 cm. The average age was 52 years, and the female to male ratio was 3.1. Two distinct categories were delineated: (1) injury-related polyps (n=273): (a) Fibro(myo)glandular polyps (n=214) were small (mean=0.4 cm), broad-based, often multiple (45%), almost always (98%) gallstone-associated, and were composed of a mixture of (myo)fibroblastic tissue/lobular glandular units with chronic cholecystitis. Dysplasia seen in 9% seemed to be secondary involvement. (b) Metaplastic pyloric glands forming polypoid collections (n=42). (c) Inflammatory-type polyps associated with acute/subacute injury (11 granulation tissue, 3 xanthogranulomatous, 3 lymphoid). (2) Cholesterol polyps (n=174) occurred in uninjured gallbladders, revealing a very thin stalk, edematous cores devoid of glands but with cholesterol-laden macrophages in 85%, and cholesterolosis in the uninvolved mucosa in 60%. Focal low-grade dysplasia was seen in 3%, always confined to the polyp, unaccompanied by carcinoma. In conclusion, non-neoplastic polyps are seen in 3% of cholecystectomies and are often small. Injury-related fibromyoglandular polyps are the most common. Cholesterol polyps have distinctive cauliflower architecture, often in a background of uninjured gallbladders with cholesterolosis and may lack the cholesterol-laden macrophages in the polyp itself. Although dysplastic changes can involve non-neoplastic polyps, they do not seem to be the cause of invasive carcinoma by themselves.

doi: https://doi.org/10.1097/PAS.0000000000001405

- Recurrent Rearrangements in PRKACA and PRKACB in Intraductal Oncocytic Papillary Neoplasms of the Pancreas and��Bile Duct

Gastroenterology 2020 02;158(3):573-582.e2

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31678302

BACKGROUND & AIMS: Intraductal oncocytic papillary neoplasms (IOPNs) of the pancreas and bile duct contain epithelial cells with numerous, large mitochondria and are cystic precursors to pancreatic ductal adenocarcinoma (PDAC) and cholangiocarcinoma (CCA), respectively. However, IOPNs do not have the genomic alterations found in other pancreatobiliary neoplasms. In fact, no recurrent genomic alterations have been described in IOPNs. PDACs without activating mutations in KRAS contain gene rearrangements, so we investigated whether IOPNs have recurrent fusions in genes. METHODS: We analyzed 20 resected pancreatic IOPNs and 3 resected biliary IOPNs using a broad RNA-based targeted sequencing panel to detect cancer-related fusion genes. Four invasive PDACs and 2 intrahepatic CCAs from the same patients as the IOPNs, were also available for analysis. Samples of pancreatic cyst fluid (n = 5, collected before surgery) and bile duct brushings (n = 2) were analyzed for translocations. For comparison, we analyzed pancreatobiliary lesions from 126 patients without IOPN (controls). RESULTS: All IOPNs evaluated were found to have recurring fusions of ATP1B1-PRKACB (n = 13), DNAJB1-PRKACA (n = 6), or ATP1B1-PRKACA (n = 4). These fusions also were found in corresponding invasive PDACs and intrahepatic CCAs, as well as in matched pancreatic cyst fluid and bile duct brushings. These gene rearrangements were absent from all 126 control pancreatobiliary lesions. CONCLUSIONS: We identified fusions in PRKACA and PRKACB genes in pancreatic and biliary IOPNs, as well as in PDACs and pancreatic cyst fluid and bile duct cells from the same patients. We did not identify these gene fusions in 126 control pancreatobiliary lesions. These fusions might be used to identify patients at risk for IOPNs and their associated invasive carcinomas.

doi: https://doi.org/10.1053/j.gastro.2019.10.028

- DNAJB1-PRKACA fusions occur in oncocytic pancreatic and biliary neoplasms and are not specific for fibrolamellar hepatocellular carcinoma

Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 2020 04;33(4):648-656

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31676785

Recently discovered DNAJB1-PRKACA oncogenic fusions have been considered diagnostic for fibrolamellar hepatocellular carcinoma. In this study, we describe six pancreatobiliary neoplasms with PRKACA fusions, five of which harbor the DNAJB1-PRKACA fusion. All neoplasms were subjected to a hybridization capture-based next-generation sequencing assay (MSK-IMPACT), which enables the identification of sequence mutations, copy number alterations, and selected structural rearrangements involving ≥410 genes (n = 6) and/or to a custom targeted, RNA-based panel (MSK-Fusion) that utilizes Archer Anchored Multiplex PCR technology and next-generation sequencing to detect gene fusions in 62 genes (n = 2). Selected neoplasms also underwent FISH analysis, albumin mRNA in-situ hybridization, and arginase-1 immunohistochemical labeling (n = 3). Five neoplasms were pancreatic, and one arose in the intrahepatic bile ducts. All revealed at least focal oncocytic morphology: three cases were diagnosed as intraductal oncocytic papillary neoplasms, and three as intraductal papillary mucinous neoplasms with mixed oncocytic and pancreatobiliary or gastric features. Four cases had an invasive carcinoma component composed of oncocytic cells. Five cases revealed DNAJB1-PRKACA fusions and one revealed an ATP1B1-PRKACA fusion. None of the cases tested were positive for albumin or arginase-1. Our data prove that DNAJB1-PRKACA fusion is neither exclusive nor diagnostic for fibrolamellar hepatocellular carcinoma, and caution should be exercised in diagnosing liver tumors with DNAJB1-PRKACA fusions as fibrolamellar hepatocellular carcinoma, particularly if a pancreatic lesion is present. Moreover, considering DNAJB1-PRKACA fusions lead to upregulated protein kinase activity and that this upregulated protein kinase activity has a significant role in tumorigenesis of fibrolamellar hepatocellular carcinoma, protein kinase inhibition could have therapeutic potential in the treatment of these pancreatobiliary neoplasms as well, once a suitable drug is developed.

doi: https://doi.org/10.1038/s41379-019-0398-2

- Clinicopathologic Characteristics of Gallbladder Adenomyomas and the Contribution of Macroscopic Sampling in Adenomyoma Diagnosis

Turk patoloji dergisi 2020 10;36(1):11-16

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31633192

OBJECTIVE: Adenomyoma, a reactive and hamartomatous lesion of the gallbladder, is included in the differential diagnosis of several benign and malignant lesions. Macroscopic sampling is very important in the determination of these lesions. The agreed macroscopy protocol in recent years has been prepared by the Hepatopancreatobiliary Pathology Working Group. We aimed to evaluate the clinicopathologic properties of adenomyoma cases in the gallbladder and the contribution of new macroscopy techniques to the diagnosis of adenomyoma in the pre-protocol and post-protocol parts of a one-year period. MATERIAL AND METHOD: Two institutes were included in the study. Adenomyoma cases diagnosed in the pre-protocol and post-protocol periods of one year duration were included in the study. Slides and demographic properties of the cases were reexamined. RESULTS: While adenomyoma was present in 22 of 1879 gallbladder before the protocol, it was observed in 32 of 1781 gallbladders in the post-protocol period. 17 of the cases were male and 37 were female. The mean age of the cases was 51.8. 52% of the lesions were located in the fundus. A gallstone was observed in 37 cases, and cholesterolosis in 14 cases. In the comparison of the two periods, the number of cases was lower in the post-protocol period but a 0.6% increase in the diagnosis of adenomyoma was found. CONCLUSION: Adenomyoma is one of the lesions of the gallbladder that should be recognized but can be easily overlooked macroscopically. When we conducted the sampling according to the last protocol, the increase in the diagnosis of adenomyoma showed that adequate and accurate sampling was very useful for the detection of adenomyoma in the gallbladder.

doi: https://doi.org/10.5146/tjpath.2019.01471

- Exome sequencing of 22 genes using tissue from patients with biliary tract cancer

APMIS : acta pathologica, microbiologica, et immunologica Scandinavica 2020 Jan;128(1):3-9

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31628675

Biliary tract cancers (BTC) are a rare heterogeneous disease group with a dismal prognosis and limited treatment options. The mutational landscape consists of genetic aberrations both shared by and characteristic for anatomical location. Here, we present exome sequencing data on 22 genes from a phase 2 trial using a clinically validated panel used in patients with colorectal cancer. A total of 56 patients were included in a one-armed phase 2 trial investigating the treatment combination of capecitabine, gemcitabine, oxaliplatin, and cetuximab. Tissue DNA yield and quality allowed analysis of 30 patients on our panel including 22 genes. ARID1A (33%) and TP53 (33%) were found to be most frequently mutated followed by KRAS mutations found in 20% of the patients. Mutational aberrations in ARID1A were found more prevalent than expected, whereas TP53 and KRAS were in concordance with earlier reported data. Mutation in CTNNB1 was significantly associated with poor prognosis. Our panel is clinically validated and suitable for a high volume of samples to detect mutations in patients with BTC. However, it is reasonable to assume that the clinical utility could be optimized in this patient group by extending the panel to include BTC specific mutations with potential therapeutic consequences such as IDH1/2, FGFR fusions, ERBB3, and BRCA1/2.

doi: https://doi.org/10.1111/apm.13003

- RET gene rearrangements occur in a subset of pancreatic acinar cell carcinomas

Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 2020 04;33(4):657-664

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31558784

Pancreatic acinar cell carcinoma is relatively rare (1 to 2% of pancreatic malignancies) but may be under-recognized. In contrast to pancreatic ductal adenocarcinoma, most acinar cell carcinomas lack mutations in KRAS, DPC, CDKN2A or TP53, but appear to have a high incidence of gene rearrangements, with up to 20% reported to be driven by BRAF fusions. With the development of a new class of RET-specific tyrosine kinase inhibitors, which appear to have particularly strong activity against RET gene rearranged tumours, there is now considerable interest in identifying RET gene rearrangements across a wide range of cancers. RET rearrangements have been reported to occur at a very low incidence (<1%) in all pancreatic carcinomas. We postulated that given its unique molecular profile, RET gene rearrangements may be common in acinar cell carcinomas. We performed fluorescent in-situ hybridization (FISH) studies on a cohort of 40 acinar cell spectrum tumours comprising 36 pure acinar cell carcinomas, three pancreatoblastomas and one mixed acinar-pancreatic neuroendocrine tumour. RET gene rearrangements were identified in 3 (7.5%) cases and BRAF gene rearrangements in 5 (12.5%). All gene rearranged tumours were pure acinar cell carcinomas. Our findings indicate that amongst all pancreatic carcinomas, acinar carcinomas are highly enriched for potentially actionable gene rearrangements in RET or BRAF. FISH testing is inexpensive and readily available in the routine clinical setting and may have a role in the assessment of all acinar cell carcinomas-at this stage to recruit patients for clinical trials of new targeted therapies, but perhaps in the near future as part of routine care.

doi: https://doi.org/10.1038/s41379-019-0373-y

- Brush Cytology Performance for the Assessment of Biliopancreatic Strictures

Acta cytologica 2019 Sep;():1-8

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31550713

INTRODUCTION: Brush cytology is commonly used during endoscopic retrograde cholangiopancreatography for the diagnostic evaluation of biliopancreatic strictures. However, since the overall sensitivity of brush cytology is poor, the exclusion of malignancy is difficult. Recognition of factors related to the patient, technique or lesion may help improve the diagnostic yield of brush cytology. The objective of this study was to evaluate the diagnostic yield of brush cytology in the assessment of biliopancreatic strictures and identify predictive factors associated with a positive diagnosis of malignancy. METHODS: Retrospective study that evaluated all consecutive patients that underwent brush cytology for the investigation of biliopancreatic strictures in a tertiary center, between January 2012 and January 2018. RESULTS: One hundred and sixty-five patients that underwent 182 procedures were included. A diagnosis of malignancy was confirmed in 110 patients (66.7%), of whom 62 had positive brush cytology (sensitivity 53.7%, specificity 98.5%, accuracy 69.8%). On the multivariate analysis, age ≥68 years (OR 4.83, 95% CI 1.04-22.37) and lesions suspicious of metastasis on cross-sectional imaging (OR 8.58, 95% CI 1.70-43.38) were independently associated with a positive result. Subanalysis of the patients presenting with these two factors (n = 26) revealed an increase in the diagnostic yield (sensitivity 80.8%). CONCLUSION: Age ≥68 years and lesions suspicious of metastasis on cross-sectional imaging are independent factors associated with a positive result. Patient selection taking these factors into account may increase the diagnostic yield of brush cytology.

doi: https://doi.org/10.1159/000502791

- Immunohistochemical profiling of liver metastases and matched-pair analysis in patients with metastatic pancreatic ductal adenocarcinoma

Pancreatology : official journal of the International Association of Pancreatology (IAP) … [et al.] 2019 Oct;19(7):963-970

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31542399

BACKGROUND: The purpose of the current study was to investigate the immunohistochemical (IHC) profile of liver metastases (LM) in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: Expression of 15 IHC markers in liver biopsies from 77 patients with PDAC, who were diagnosed between 2010 and 2014, were evaluated. In a separate subgroup analysis (n = 12), paired samples (LM and primary tumor) from the same patient were investigated for IHC profile differences. RESULTS: LM samples were classified as pancreatobiliary-type (PB-type) in 72 patients (93.5%), intestinal-type (INT-type) in four patients (5.2%), and squamous in one patient (1.3%). There was no significant difference in overall survival (OS) between LM of the PB-type or INT-type (p = 0.097). In a multivariate analysis, age <70 years (p = 0.047), absence of SMAD4 mutation (p = 0.026), absence of CDX2 expression (p = 0.003), and well to moderate differentiation were significant prognostic factors for better OS in patients with LM (p = 0.031). Analysis of paired tissue samples from LM and the primary tumor revealed a difference in CDX2 (50% increase, p = 0.125) and SMAD4 (33% loss of SMAD4, p = 0.375). CONCLUSIONS: CDX2 expression and SMAD4 mutation indicate a poor outcome in patients with LM of PDAC. Matched-pair analysis revealed differences in distinct IHC marker expression.

doi: https://doi.org/10.1016/j.pan.2019.09.005

- Clinicopathological features of pyloric gland adenomas of the duodenum: a multicentre study of 57 cases

Histopathology 2020 Feb;76(3):404-410

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31529725

AIMS: To determine the clinicopathological features of pyloric gland adenomas (PGA) that arise in the duodenum. METHODS AND RESULTS: Fifty-seven cases of duodenal PGA were identified and analysed from 56 patients. Clinicopathological and immunohistochemical analyses were performed. PGA tend to occur in older individuals (median age = 73.5), with a slight female predominance (25 males, 31 females). PGA arise more commonly in the proximal duodenum (68.75% in D1, 25% in D2 and 6.25% in D3) and usually present as mucosal nodules (98.2%) or plaques (1.8%), with a mean size of 14.8 mm. There is associated gastric heterotopia in 22.8% of cases. PGA showing features of high-grade dysplasia were significantly larger in size than PGA, showing only low-grade dysplasia (23.1 versus 8.7 mm; P = 0.0001) and more likely to show a tubulovillous rather than a pure tubular architecture (P = 0.025). In our series, 10 of 56 patients had intramucosal or invasive carcinoma associated with the duodenal PGA (17.9%). Three of these carcinomas showed lymph node metastasis. Following definitive treatment, local recurrence occurred in only three patients. CONCLUSIONS: Duodenal PGA tend to occur in the proximal duodenum of older individuals. Larger size and tubulovillous architecture correlates with high-grade dysplasia and associated adenocarcinoma. The low recurrence rate of these lesions would suggest that endoscopic management is appropriate, provided that the lesion can be completely resected.

doi: https://doi.org/10.1111/his.13996

- Comparison of the clinicopathological features of pancreatic solid pseudopapillary neoplasms between males and females: gender does matter

Histology and histopathology 2020 Mar;35(3):257-268

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31478554

BACKGROUND: Solid pseudopapillary neoplasms (SPN) of the pancreas are a rare and low-grade malignant entity with a female predominance. However, it also occurs in males, but the rarity and lack of concern makes its clinicopathological features unclarified. METHODS: The morphological, immunohistochemical, prognostic features and CTNNB1 exon 3 mutation status of SPN were compared semi-quantitively between 9 male and 21 female patients. RESULTS: SPN in males grew in a distinctive solid pattern, with abundant fibrotic stroma and clear cells. Collagen tended to be the main component of tumor stroma in males, while hyaluronan composed a considerable proportion in females. A much stronger expression of androgen receptor (AR) was found in males, and CD56 and/or synaptophysin (Syn) was expressed frequently in both genders. All patients survived. One male patient had post-operational liver nodules and accepted interventional therapy without biopsy. Mutations of CTNNB1 exon 3 were observed in all cases, distributed at codon 32, 33 and 37 in both genders, as well as 34, 41 and 62 in females. CONCLUSION: SPN in males presented with significantly different morphological features from that in females, which might be helpful in differential diagnosis, especially when with extensive positivity for CD56 and/or Syn. The stronger expression of AR in males might be a clue to explore the underlying mechanism of the gender difference.

doi: https://doi.org/10.14670/HH-18-156

- Whole-genome sequencing reveals distinct genetic bases for insulinomas and non-functional pancreatic neuroendocrine tumours: leading to a new classification system

Gut 2020 May;69(5):877-887

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31462556

OBJECTIVE: Insulinomas and non-functional pancreatic neuroendocrine tumours (NF-PanNETs) have distinctive clinical presentations but share similar pathological features. Their genetic bases have not been comprehensively compared. Herein, we used whole-genome/whole-exome sequencing (WGS/WES) to identify genetic differences between insulinomas and NF-PanNETs. DESIGN: The mutational profiles and copy-number variation (CNV) patterns of 211 PanNETs, including 84 insulinomas and 127 NF-PanNETs, were obtained from WGS/WES data provided by Peking Union Medical College Hospital and the International Cancer Genome Consortium. Insulinoma RNA sequencing and immunohistochemistry data were assayed. RESULTS: PanNETs were categorised based on CNV patterns: amplification, copy neutral and deletion. Insulinomas had CNV amplifications and copy neutral and lacked CNV deletions. CNV-neutral insulinomas exhibited an elevated rate of YY1 mutations. In contrast, NF-PanNETs had all three CNV patterns, and NF-PanNETs with CNV deletions had a high rate of loss-of-function mutations of tumour suppressor genes. NF-PanNETs with CNV alterations (amplification and deletion) had an elevated risk of relapse, and additional DAXX/ATRX mutations could predict an increased relapse risk in the first 2-year period. CONCLUSION: These WGS/WES data allowed a comprehensive assessment of genetic differences between insulinomas and NF-PanNETs, reclassifying these tumours into novel molecular subtypes. We also proposed a novel relapse risk stratification system using CNV patterns and DAXX/ATRX mutations.

doi: https://doi.org/10.1136/gutjnl-2018-317233

- Cell block processing is optimal for assessing endoscopic ultrasound fine needle aspiration specimens of pancreatic mucinous cysts

Journal of clinical pathology 2020 Feb;73(2):102-106

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31462450

AIMS: The cell block technique for assessing endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) specimens from pancreatic mucinous cystic lesions (MCLs) was systematically evaluated for the first time, including comparisons with three traditional methods of assessing such specimens. METHODS: The prospective arm comprised EUS-FNA specimens from EUS-suspected pancreatic MCLs. The retrospective arm comprised EUS-FNA specimens from pancreatic MCLs surgically resected before the study start. For each specimen, these data points were collected: macroscopic likelihood of mucin, cyst fluid carcinoembryonic antigen (CEA) level and presence of mucin in air-dried, direct smears and in cell block preparations. RESULTS: The prospective and retrospective arms of the study comprised 80 and 30 EUS-FNA specimens, respectively. Seven prospective cases led to surgical resections during the study, and therefore, 37 EUS-FNA specimens were confirmed to have originated from MCLs. In the prospective arm, macroscopic mucin was suspected, cyst fluid CEA level exceeded 192 ng/mL, mucin was detected in direct smears and cell block preparations in 78%, 30%, 39% and 73% of cases, respectively. Of the 37 specimens confirmed to originate from MCLs, macroscopic mucin assessment, cyst fluid CEA level, direct smear mucin assessment and cell block mucin assessment had sensitivities for diagnosing MCL of 87%, 45%, 45% and 81%, respectively. CONCLUSIONS: Cell block preparations are as likely to identify mucin from pancreatic MCLs as macroscopic assessment but are twice as likely to diagnose MCL than direct smears and fluid CEA biochemistry. The cell block technique is easy for sample collection and processing especially because these are identical for solid and cystic pancreatic lesions.

doi: https://doi.org/10.1136/jclinpath-2019-206079

- Grading Pancreatic Neuroendocrine Tumors by Ki-67 Index Evaluated on Fine-Needle Aspiration Cell Block Material

American journal of clinical pathology 2020 01;153(1):74-81

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31415691

OBJECTIVES: This study aimed to determine whether Ki-67 index evaluated on cytologic material could reliably grade pancreatic neuroendocrine tumors (PanNETs). METHODS: Cases with adequate cell block and available surgical specimens were included. Ki-67 index was calculated using “eyeballing,” “hot spot,” and “complete” counting methods. RESULTS: The overall concordance rates between cytology and surgical specimens were 71%, 73%, and 59%, respectively, by using eyeballing, hot spot, and complete counting approaches. All grade 1 tumors were correctly graded on cytology, but in grade 2 tumors concordance rates were only 36%, 41%, and 9%, respectively. All grade 2 tumors were undergraded when cell blocks contained fewer than 1,000 cells, while concordance rate increased to 57%, 64%, and 14%, respectively, in cases with 1,000 cells or more. CONCLUSIONS: Grade 2 PanNETs can be significantly undergraded when Ki-67 index is evaluated on cell block material. In cases with 1,000 or more cells, the hot spot counting method has better correlation with surgical specimens.

doi: https://doi.org/10.1093/ajcp/aqz110

- Sclerosing epithelioid mesenchymal neoplasm of the pancreas��-��a proposed new entity

Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 2020 03;33(3):456-467

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31383964

We have encountered pancreatic tumors with unique histologic features, which do not conform to any of the known tumors of the pancreas or other anatomical sites. We aimed to define their clinicopathologic features and whether they are characterized by recurrent molecular signatures. Eight cases were identified; studied histologically and by immunohistochemistry. Selected cases were also subjected to whole-exome sequencing (WES; n = 4), RNA-sequencing (n = 6), Archer FusionPlex assay (n = 5), methylation profiling using the Illumina MethylationEPIC (850k) array platform (n = 6), and TERT promoter sequencing (n = 5). Six neoplasms occurred in females. The mean age was 43 years (range: 26-75). Five occurred in the head/neck of the pancreas. All patients were treated surgically; none received neoadjuvant/adjuvant therapy. All patients are free of disease after 53 months of median follow-up (range: 8-94). The tumors were well-circumscribed, and the median size was 1.8 cm (range: 1.3-5.8). Microscopically, the unencapsulated tumors had a geographic pattern of epithelioid cell nests alternating with spindle cell fascicles. Some areas showed dense fibrosis, in which enmeshed tumor cells imparted a slit-like pattern. The predominant epithelioid cells had scant cytoplasm and round-oval nuclei with open chromatin. The spindle cells displayed irregular, hyperchromatic nuclei. Mitoses were rare. No lymph node metastases were identified. All tumors were positive for vimentin, CD99 and cytokeratin (patchy), while negative for markers of solid pseudopapillary neoplasm, neuroendocrine, acinar, myogenic/rhabdoid, vascular, melanocytic, or lymphoid differentiation, gastrointestinal stromal tumor as well as MUC4. Whole-exome sequencing revealed no recurrent somatic mutations or amplifications/homozygous deletions in any known oncogenes or tumor suppressor genes. RNA-sequencing and the Archer FusionPlex assay did not detect any recurrent likely pathogenic gene fusions. Single sample gene set enrichment analysis revealed that these tumors display a likely mesenchymal transcriptomic program. Unsupervised analysis (t-SNE) of their methylation profiles against a set of different mesenchymal neoplasms demonstrated a distinct methylation pattern. Here, we describe pancreatic neoplasms with unique morphologic/immunophenotypic features and a distinct methylation pattern, along with a lack of abnormalities in any of key genetic drivers, supporting that these neoplasms represent a novel entity with an indolent clinical course. Given their mesenchymal transcriptomic features, we propose the designation of “sclerosing epithelioid mesenchymal neoplasm” of the pancreas.

doi: https://doi.org/10.1038/s41379-019-0334-5

- New Nodal Staging for Primary Pancreatic Neuroendocrine Tumors: A Multi-institutional and National Data Analysis

Annals of surgery 2019 Jul;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31356277

OBJECTIVE: To determine the prognostic role of metastatic lymph node (LN) number and the minimal number of LNs for optimal staging of patients with pancreatic neuroendocrine tumors (pNETs). BACKGROUND: Prognosis relative to number of LN metastasis (LNM), and minimal number of LNs needed to evaluate for accurate staging, have been poorly defined for pNETs. METHODS: Number of LNM and total number of LN evaluated (TNLE) were assessed relative to recurrence-free survival (RFS) and overall survival (OS) in a multi-institutional database. External validation was performed using Surveillance, Epidemiology and End Results (SEER) registry. RESULTS: Among 854 patients who underwent resection, 233 (27.3%) had at least 1 LNM. Patients with 1, 2, or 3 LNM had a comparable worse RFS versus patients with no nodal metastasis (5-year RFS, 1 LNM 65.6%, 2 LNM 68.2%, 3 LNM 63.2% vs 0 LNM 82.6%; all P < 0.001). In contrast, patients with ≥4 LNM (proposed N2) had a worse RFS versus patients who either had 1 to 3 LNM (proposed N1) or node-negative disease (5-year RFS, ≥4 LNM 43.5% vs 1-3 LNM 66.3%, 0 LNM 82.6%; all P < 0.05) [C-statistics area under the curve (AUC) 0.650]. TNLE ≥8 had the highest discriminatory power relative to RFS (AUC 0.713) and OS (AUC 0.726) among patients who had 1 to 3 LNM, and patients who had ≥4 LNM in the multi-institutional and SEER database (n = 2764). CONCLUSIONS: Regional lymphadenectomy of at least 8 lymph nodes was necessary to stage patients accurately. The proposed nodal staging of N0, N1, and N2 optimally staged patients.

doi: https://doi.org/10.1097/SLA.0000000000003478

- The Presence of Pericholedochal Hyaline Cartilage in Biliary Atresia: A Report and A Review

Fetal and pediatric pathology 2020 Apr;39(2):156-162

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31314631

Background: The presence of cartilage in extra hepatic biliary tree is an unusual finding. An isolated presence of the cartilage is possibly heterotopic or occurs as a metaplastic response to the inflammatory insult.Material and methods: We had examined the liver biopsy and the resected specimen of a biliary atresia (BA) after Kasai procedure.Results: There was hyaline cartilage around the common hepatic and common bile duct in a 3-months-old male infant with distal obstructive cholangiopathy on liver biopsy and had positive serum IgM for cytomegalovirus (CMV). Similar findings could not be documented in the pericholedochal tissue of any of the 25 other pediatric cases operated for BA or choledochal cyst and three neonatal autopsies performed for liver-related deaths.Conclusion: Peri-bile duct cartilage is a unique finding and could represent an unusual form of heterotopia or connective tissue metaplasia.

doi: https://doi.org/10.1080/15513815.2019.1639091

- Development of the Intrahepatic and Extrahepatic Biliary Tract: A Framework for Understanding Congenital Diseases

Annual review of pathology 2020 01;15():1-22

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31299162

The involvement of the biliary tract in the pathophysiology of liver diseases and the increased attention paid to bile ducts in the bioconstruction of liver tissue for regenerative therapy have fueled intense research into the fundamental mechanisms of biliary development. Here, I review the molecular, cellular and tissular mechanisms driving differentiation and morphogenesis of the intrahepatic and extrahepatic bile ducts. This review focuses on the dynamics of the transcriptional and signaling modules that promote biliary development in human and mouse liver and discusses studies in which the use of zebrafish uncovered unexplored processes in mammalian biliary development. The review concludes by providing a framework for interpreting the mechanisms that may help us understand the origin of congenital biliary diseases.

doi: https://doi.org/10.1146/annurev-pathmechdis-012418-013013

- Significance of Lymph Node Metastasis in Resectable Well-differentiated Pancreatic Neuroendocrine Tumor

Pancreas 2019 08;48(7):943-947

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31268980

OBJECTIVES: Understanding the effect of lymph node metastasis (LNM) on prognosis in pancreatic neuroendocrine neoplasm is helpful for surgery and follow-up. In this study, we investigated the significance of LNM in well-differentiated pancreatic neuroendocrine tumors (PanNETs) according to the World Health Organization 2017 classification. METHODS: We retrospectively collected data for 95 consecutive patients with PanNET who underwent pancreatic resection with curative intent between January 2008 and December 2017 at 6 institutions. The clinicopathological factors were compared in patients with and without LNM, and prognostic factors were analyzed. RESULTS: Lymph node metastasis was significantly associated with malignant potential of PanNET, such as larger tumor size, higher Ki-67 index, higher tumor grade, and higher incidence of lymphatic, vessel, and neural invasion. Lymph node metastasis was also associated with disease-free but not overall survival. Multivariate analysis identified NET grade 2 (G2) and G3 as independent risk factors for recurrence after curative resection. CONCLUSIONS: World Health Organization 2017 classification was the most independent prognostic factor in patients with resectable well-differentiated PanNETs. Patients with G2 and higher-grade tumors require lymph node dissection to improve prognosis.

doi: https://doi.org/10.1097/MPA.0000000000001355

- Morphological classification of pancreatic ductal adenocarcinoma that predicts molecular subtypes and correlates with clinical outcome

Gut 2020 02;69(2):317-328

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31201285

INTRODUCTION: Transcriptional analyses have identified several distinct molecular subtypes in pancreatic ductal adenocarcinoma (PDAC) that have prognostic and potential therapeutic significance. However, to date, an indepth, clinicomorphological correlation of these molecular subtypes has not been performed. We sought to identify specific morphological patterns to compare with known molecular subtypes, interrogate their biological significance, and furthermore reappraise the current grading system in PDAC. DESIGN: We first assessed 86 primary, chemotherapy-naive PDAC resection specimens with matched RNA-Seq data for specific, reproducible morphological patterns. Differential expression was applied to the gene expression data using the morphological features. We next compared the differentially expressed gene signatures with previously published molecular subtypes. Overall survival (OS) was correlated with the morphological and molecular subtypes. RESULTS: We identified four morphological patterns that segregated into two components (‘gland forming’ and ‘non-gland forming’) based on the presence/absence of well-formed glands. A morphological cut-off (≥40% ‘non-gland forming’) was established using RNA-Seq data, which identified two groups (A and B) with gene signatures that correlated with known molecular subtypes. There was a significant difference in OS between the groups. The morphological groups remained significantly prognostic within cancers that were moderately differentiated and classified as ‘classical’ using RNA-Seq. CONCLUSION: Our study has demonstrated that PDACs can be morphologically classified into distinct and biologically relevant categories which predict known molecular subtypes. These results provide the basis for an improved taxonomy of PDAC, which may lend itself to future treatment strategies and the development of deep learning models.

doi: https://doi.org/10.1136/gutjnl-2019-318217

- Circulating Tumor DNA as a Clinical Test in Resected Pancreatic Cancer

Clinical cancer research : an official journal of the American Association for Cancer Research 2019 08;25(16):4973-4984

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31142500

PURPOSE: In research settings, circulating tumor DNA (ctDNA) shows promise as a tumor-specific biomarker for pancreatic ductal adenocarcinoma (PDAC). This study aims to perform analytical and clinical validation of a KRAS ctDNA assay in a Clinical Laboratory Improvement Amendments (CLIA) and College of American Pathology-certified clinical laboratory. EXPERIMENTAL DESIGN: Digital-droplet PCR was used to detect the major PDAC-associated somatic KRAS mutations (G12D, G12V, G12R, and Q61H) in liquid biopsies. For clinical validation, 290 preoperative and longitudinal postoperative plasma samples were collected from 59 patients with PDAC. The utility of ctDNA status to predict PDAC recurrence during follow-up was assessed. RESULTS: ctDNA was detected preoperatively in 29 (49%) patients and was an independent predictor of decreased recurrence-free survival (RFS) and overall survival (OS). Patients who had neoadjuvant chemotherapy were less likely to have preoperative ctDNA than were chemo-naïve patients (21% vs. 69%; P < 0.001). ctDNA levels dropped significantly after tumor resection. Persistence of ctDNA in the immediate postoperative period was associated with a high rate of recurrence and poor median RFS (5 months). ctDNA detected during follow-up predicted clinical recurrence [sensitivity 90% (95% confidence interval (CI), 74%-98%), specificity 88% (95% CI, 62%-98%)] with a median lead time of 84 days (interquartile range, 25-146). Detection of ctDNA during postpancreatectomy follow-up was associated with a median OS of 17 months, while median OS was not yet reached at 30 months for patients without ctDNA (P = 0.011). CONCLUSIONS: Measurement of KRAS ctDNA in a CLIA laboratory setting can be used to predict recurrence and survival in patients with PDAC.

doi: https://doi.org/10.1158/1078-0432.CCR-19-0197

- Regulation of pH by Carbonic Anhydrase 9 Mediates Survival of Pancreatic Cancer Cells With Activated KRAS in Response to Hypoxia

Gastroenterology 2019 09;157(3):823-837

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31078621

BACKGROUND & AIMS: Most pancreatic ductal adenocarcinomas (PDACs) express an activated form of KRAS, become hypoxic and dysplastic, and are refractory to chemo and radiation therapies. To survive in the hypoxic environment, PDAC cells upregulate enzymes and transporters involved in pH regulation, including the extracellular facing carbonic anhydrase 9 (CA9). We evaluated the effect of blocking CA9, in combination with administration of gemcitabine, in mouse models of pancreatic cancer. METHODS: We knocked down expression of KRAS in human (PK-8 and PK-1) PDAC cells with small hairpin RNAs. Human and mouse (KrasG12D/Pdx1-Cre/Tp53/RosaYFP) PDAC cells were incubated with inhibitors of MEK (trametinib) or extracellular signal-regulated kinase (ERK), and some cells were cultured under hypoxic conditions. We measured levels and stability of the hypoxia-inducible factor 1 subunit alpha (HIF1A), endothelial PAS domain 1 protein (EPAS1, also called HIF2A), CA9, solute carrier family 16 member 4 (SLC16A4, also called MCT4), and SLC2A1 (also called GLUT1) by immunoblot analyses. We analyzed intracellular pH (pHi) and extracellular metabolic flux. We knocked down expression of CA9 in PDAC cells, or inhibited CA9 with SLC-0111, incubated them with gemcitabine, and assessed pHi, metabolic flux, and cytotoxicity under normoxic and hypoxic conditions. Cells were also injected into either immune-compromised or immune-competent mice and growth of xenograft tumors was assessed. Tumor fragments derived from patients with PDAC were surgically ligated to the pancreas of mice and the growth of tumors was assessed. We performed tissue microarray analyses of 205 human PDAC samples to measure levels of CA9 and associated expression of genes that regulate hypoxia with outcomes of patients using the Cancer Genome Atlas database. RESULTS: Under hypoxic conditions, PDAC cells had increased levels of HIF1A and HIF2A, upregulated expression of CA9, and activated glycolysis. Knockdown of KRAS in PDAC cells, or incubation with trametinib, reduced the posttranscriptional stabilization of HIF1A and HIF2A, upregulation of CA9, pHi, and glycolysis in response to hypoxia. CA9 was expressed by 66% of PDAC samples analyzed; high expression of genes associated with metabolic adaptation to hypoxia, including CA9, correlated with significantly reduced survival times of patients. Knockdown or pharmacologic inhibition of CA9 in PDAC cells significantly reduced pHi in cells under hypoxic conditions, decreased gemcitabine-induced glycolysis, and increased their sensitivity to gemcitabine. PDAC cells with knockdown of CA9 formed smaller xenograft tumors in mice, and injection of gemcitabine inhibited tumor growth and significantly increased survival times of mice. In mice with xenograft tumors grown from human PDAC cells, oral administration of SLC-0111 and injection of gemcitabine increased intratumor acidosis and increased cell death. These tumors, and tumors grown from PDAC patient-derived tumor fragments, grew more slowly than xenograft tumors in mice given control agents, resulting in longer survival times. In KrasG12D/Pdx1-Cre/Tp53/RosaYFP genetically modified mice, oral administration of SLC-0111 and injection of gemcitabine reduced numbers of B cells in tumors. CONCLUSIONS: In response to hypoxia, PDAC cells that express activated KRAS increase expression of CA9, via stabilization of HIF1A and HIF2A, to regulate pH and glycolysis. Disruption of this pathway slows growth of PDAC xenograft tumors in mice and might be developed for treatment of pancreatic cancer.

doi: https://doi.org/10.1053/j.gastro.2019.05.004

- NRG1 Gene Fusions Are Recurrent, Clinically Actionable Gene Rearrangements in KRAS Wild-Type Pancreatic Ductal Adenocarcinoma

Clinical cancer research : an official journal of the American Association for Cancer Research 2019 Aug;25(15):4674-4681

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31068372

PURPOSE: Gene fusions involving neuregulin 1 (NRG1) have been noted in multiple cancer types and have potential therapeutic implications. Although varying results have been reported in other cancer types, the efficacy of the HER-family kinase inhibitor afatinib in the treatment of NRG1 fusion-positive pancreatic ductal adenocarcinoma is not fully understood. EXPERIMENTAL DESIGN: Forty-seven patients with pancreatic ductal adenocarcinoma received comprehensive whole-genome and transcriptome sequencing and analysis. Two patients with gene fusions involving NRG1 received afatinib treatment, with response measured by pretreatment and posttreatment PET/CT imaging. RESULTS: Three of 47 (6%) patients with advanced pancreatic ductal adenocarcinoma were identified as KRAS wild type by whole-genome sequencing. All KRAS wild-type tumors were positive for gene fusions involving the ERBB3 ligand NRG1. Two of 3 patients with NRG1 fusion-positive tumors were treated with afatinib and demonstrated a significant and rapid response while on therapy. CONCLUSIONS: This work adds to a growing body of evidence that NRG1 gene fusions are recurrent, therapeutically actionable genomic events in pancreatic cancers. Based on the clinical outcomes described here, patients with KRAS wild-type tumors harboring NRG1 gene fusions may benefit from treatment with afatinib.See related commentary by Aguirre, p. 4589.

doi: https://doi.org/10.1158/1078-0432.CCR-19-0191

- Loss of SMAD4 protein expression in gastrointestinal and extra-gastrointestinal carcinomas

Histopathology 2019 Oct;75(4):546-551

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31054158

AIMS: SMAD4 (DPC4) is a tumour suppressor gene that is dysregulated in various tumour types, particularly pancreaticobiliary and gastrointestinal carcinomas. Corresponding loss of protein expression has been reported in approximately 50% of pancreatic and 25% of colonic adenocarcinomas. In the evaluation of carcinoma of unknown primary site, immunohistochemical loss of SMAD4 expression is often used to suggest pancreaticobiliary origin, but there are limited data on the spectrum of SMAD4 expression in carcinomas of other sites. This study evaluates the frequency of SMAD4 loss in a large cohort of carcinomas from diverse anatomical sites. METHODS AND RESULTS: Immunohistochemistry for SMAD4 was performed on tissue microarrays or whole tissue sections of 1210 carcinomas from various organs: gastrointestinal tract, liver, pancreas/biliary tract, lung, breast, thyroid, kidney, ovary and uterus. Expression was considered lost when there was complete absence of staining in tumour cell nuclei, in the presence of intact staining in non-neoplastic cells. SMAD4 loss was seen in 58% of pancreatic adenocarcinomas, 27% of appendiceal adenocarcinomas, 19% of colorectal adenocarcinomas, 16% of cholangiocarcinomas, 10% of lung adenocarcinomas and <5% of oesophageal, breast, gastric and mucinous ovarian adenocarcinomas. All papillary thyroid, hepatocellular, non-mucinous ovarian, endometrial and renal cell carcinomas showed intact SMAD4 nuclear expression. CONCLUSION: In addition to pancreaticobiliary, appendiceal and colonic tumours, SMAD4 loss is also seen in a small subset of other carcinomas, specifically breast, lung, oesophageal and gastric adenocarcinomas, all of which are typically CK7-positive, similar to pancreaticobiliary carcinoma. Awareness of SMAD4 loss in these other carcinoma types is helpful in the evaluation of carcinomas of unknown or uncertain primary site.

doi: https://doi.org/10.1111/his.13894

- The role of rapid on-site evaluation on diagnostic accuracy of endoscopic ultrasound fine needle aspiration for pancreatic, submucosal upper gastrointestinal tract and adjacent lesions

Cytopathology : official journal of the British Society for Clinical Cytology 2019 09;30(5):499-503

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31034112

BACKGROUND AND AIM: Our aim was to assess adequacy and diagnostic accuracy of endoscopic ultrasound-fine needle aspiration (EUS-FNA) specimens with or without rapid on-site evaluation (ROSE) from pancreatic, upper gastrointestinal tract (UGIT) and adjacent masses. METHOD: A retrospective cohort study based on patients’ files who underwent EUS-FNA in Galilee Medical Center in a 4 years period. Number of needle passes, repeated EUS and ROSE effect on tissue adequacy and diagnostic accuracy were reported. RESULTS: One-hundred sixty-one patients were included. Ninety-three patients (57.7%) underwent EUS-FNA without ROSE (group A) compared to 68 patients (42.3%) with ROSE (group B). The most common location was in the pancreas (55% in group A vs 81% in group B). Addition of ROSE yielded a significantly higher specimen adequacy (65% in group A vs 92.6% in group B (Chi-Square < 0.0001, OR 6.72, 95% CI 2.45-18.38). The matching rate (accuracy) between ROSE diagnosis and final histopathological diagnosis was noticed in 61 out of 68 patients (89.7%, 95% CI 0.7993-0.9576). The Kappa coefficient correlations of matching rate between ROSE and final histopathological diagnosis of all lesion and in pancreatic lesions were 0.7558, (95% CI 0.625-0.887) and 0.7814, (95% CI 0.639-0.924), respectively. CONCLUSIONS: EUS-FNA with ROSE significantly improve specimen adequacy and was associated with high diagnostic accuracy.

doi: https://doi.org/10.1111/cyt.12712

- GNAS but Not Extended RAS Mutations Spectrum are Associated with a Better Prognosis in Intraductal Pancreatic Mucinous Neoplasms

Annals of surgical oncology 2019 Aug;26(8):2640-2650

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31025231

BACKGROUND: The management of intraductal papillary mucinous neoplasms (IPMNs) is mainly based on imaging features and clinical symptoms, and remains challenging. OBJECTIVE: The aim of this study was to assess GNAS, RAS family (KRAS, NRAS and HRAS), BRAF, and PIK3CA mutation status in resected IPMNs and correlate it with clinicopathological characteristics and patient survival. METHODS: Overall, 149 consecutive unselected patients who underwent pancreatectomy for IPMNs were included. After dissection from formalin-fixed and paraffin-embedded tumors, GNAS mutational screening was assessed by allelic discrimination using Taqman® probes and confirmed by SNaPshot analysis. RAS family, BRAF, and PIK3CA mutational screening was assessed by high resolution melt and Sanger sequencing. RESULTS: Gastric- and intestinal-type IPMNs were the most frequent lesions (52% and 41%, respectively). Intestinal-type IPMNs were more frequently associated high-grade dysplasia (49%) and were the only IPMNs associated with colloid-type carcinoma. All pancreatobiliary IPMNs were invasive lesions, located in the main pancreatic duct. GNAS-activating mutations were strongly associated with the intestinal phenotype (p < 10-4), while RAS pathway mutations were not associated with any particular phenotype. Mutations within other members of the epidermal growth factor receptor (EGFR) pathway were very rare (2%). GNAS-mutated IPMNs were rarely invasive (11%) and almost exclusively (83%) of the colloid type. For invasive lesions, multivariate analyses determined that only node negativity was associated with improved cancer-specific survival, but, in univariate analysis, GNAS mutation was associated with prolonged survival. CONCLUSION: In patients selected for surgery, GNAS mutation analysis and tumor phenotype can help to better predict patient prognosis. In the near future, a more precise mutational analysis of IPMNs might help to better tailor their management.

doi: https://doi.org/10.1245/s10434-019-07389-6

- Defining the Role of Lymphadenectomy for Pancreatic Neuroendocrine Tumors: An Eight-Institution Study of 695 Patients from the US Neuroendocrine Tumor Study Group

Annals of surgical oncology 2019 Aug;26(8):2517-2524

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=31004295

BACKGROUND: Preoperative factors that reliably predict lymph node (LN) metastases in pancreatic neuroendocrine tumors (PanNETs) are unclear. The number of LNs needed to accurately stage PanNETs has not been defined. METHODS: Patients who underwent curative-intent resection of non-functional PanNETs at eight institutions from 2000 to 2016 were analyzed. Preoperative factors associated with LN metastases were identified. A procedure-specific target for LN retrieval to accurately stage patients was determined. RESULTS: Of 695 patients who underwent resection, 33% of tumors were proximal (head/uncinate) and 67% were distal (neck/body/tail). Twenty-six percent of patients (n = 158) had LN-positive disease, which was associated with a worse 5-year recurrence-free survival (RFS; 60% vs. 86%; p < 0.001). The increasing number of positive LNs was not associated with worse RFS. Preoperative factors associated with positive LNs included tumor size ≥ 2 cm (odds ratio [OR] 6.6; p < 0.001), proximal location (OR 2.5; p < 0.001), moderate versus well-differentiation (OR 2.1; p = 0.006), and Ki-67 ≥ 3% (OR 3.1; p < 0.001). LN metastases were also present in tumors without these risk factors: < 2 cm (9%), distal location (19%), well-differentiated (23%), and Ki-67 < 3% (16%). Median LN retrieval was 13 for pancreatoduodenectomy (PD), but only 9 for distal pancreatectomy (DP). Given that PD routinely includes a complete regional lymphadenectomy, a minimum number of LNs to accurately stage patients was not identified. However, for DP, removal of less than seven LNs failed to discriminate 5-year RFS between LN-positive and LN-negative patients (less than seven LNs: 72% vs. 83%, p = 0.198; seven or more LNs: 67% vs. 86%; p = 0.002). CONCLUSIONS: Tumor size ≥ 2 cm, proximal location, moderate differentiation, and Ki-67 ≥ 3% are preoperative factors that predict LN positivity in resected non-functional PanNETs. Given the 9-23% incidence of LN metastases in patients without such risk factors, routine regional lymphadenectomy should be considered. PD inherently includes sufficient LN retrieval, while DP should aim to remove seven or more LNs for accurate staging.

doi: https://doi.org/10.1245/s10434-019-07367-y

- Clear Cell Variant of Solid Pseudopapillary Neoplasm of the Pancreas: A Report of a Rare Variant and Review of the Literature

International journal of surgical pathology 2019 Aug;27(5):535-540

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=30845855

The clear cell variant of solid pseudopapillary neoplasm (ccSPN) of the pancreas was first described in 2006. In this article, we report a case of this rare variant and review the few published reports. Both the current and previous reports show that ccSPN has several morphologic differences from conventional SPN, including clear vacuoles, fewer pseudopapillary formations, more solid/diffuse architecture, less hemorrhage, and fewer cholesterol clefts. Some of these features peculiar to ccSPN, such as solid/diffuse architecture, have been proposed to suggest aggressive behavior, though reports of ccSPN are rare and often have limited clinical follow-up. ccSPN also appears to occur more frequently in males than conventional SPNs. These clinical and pathologic features lead to unique set of differential diagnostic considerations for ccSPN, including metastatic renal cell carcinoma, perivascular epithelial cell tumor, and clear cell variants of other carcinomas. These unique features, atypical differential, and uncertain prognostic ramifications all make ccSPN an important variant to be aware of and report.

doi: https://doi.org/10.1177/1066896919833790

- STING signalling protects against chronic pancreatitis by modulating Th17 response

Gut 2019 10;68(10):1827-1837

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=30705050

OBJECTIVE: Chronic pancreatitis (CP) is an inflammatory disease with progressive fibrosis leading to exocrine and endocrine dysfunction. Currently, there are no approved effective therapies for CP. Stimulator of interferon genes (STING) signalling is a key innate immune sensor of DNA. In this study, we evaluated the role of STING signalling in CP. DESIGN: We used an experimental model of CP to test the effect of STING signalling in STING wild-type and knockout mice as well as bone marrow chimaeras (BMCs). STING was activated using a pharmacological agent. Since we found changes in Th17 cells, we used neutralising and control antibodies to determine the role of IL-17A. The effect of STING signalling was further explored in IL-17A generation and we examined the effect of IL-17A on pancreatic stellate cells (PSCs). Human pancreas from patients with CP and without CP were also stained for IL-17A. RESULTS: STING activation decreased CP-associated pancreatic inflammation and fibrosis, whereas absence of STING led to worsening of the disease. BMCs showed that leucocytes play an important role in STING signalling-mediated amelioration of experimental CP. STING deletion was associated with increased Th17 cell infiltration in the pancreas, whereas STING agonist limited this Th17 response. Importantly, anti-IL-17A antibody treatment mitigated the severity of CP in the absence of STING signalling. STING deficiency promoted Th17 polarisation and PSCs express functional IL-17 receptor by upregulating fibrosis genes. Compared with tumour margins, pancreas from patients with CP had significant increase in IL-17A+ cells. CONCLUSION: Unlike acute pancreatitis, STING activation is protective in CP. STING signalling is important in regulating adaptive immune responses by diminishing generation of IL-17A during CP and presents a novel therapeutic target for CP.

doi: https://doi.org/10.1136/gutjnl-2018-317098

- High Expression of Long Noncoding RNA HOTAIRM1 is Associated with the Proliferation and Migration in Pancreatic Ductal Adenocarcinoma

Pathology oncology research : POR 2019 Oct;25(4):1567-1577

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=30613920

Pancreatic ductal adenocarcinoma (PDAC) is an incurable malignancy. Long noncoding RNA (LncRNA) HOTAIRM1 (HOX antisense intergenic RNA myeloid 1) has been shown to play important roles in the progression of several type cancers. However, the exact role of HOTAIRM1 in PDAC development remains largely unknown. This study aims to evaluate the potential function of HOTAIRM1 in the development and progress of PDAC. HOTAIRM1 expression was measured by RT-qPCR in forty seven paired human PDAC tissues and five PDAC cell lines. SW1990 and PANC-