Hilar cholangiocarcinoma and pancreatic ductal adenocarcinoma share similar histopathologies, immunophenotypes, and development-related molecules

Ancillary tests for hepatobiliary neoplasms: what we know and what we need to know

Ancillary tests are commonly used in the surgical pathology setting for diagnosing challenging neoplastic diseases of the liver and biliary tract, while histology and clinical correlation remain to be critically important. With continuous discoveries, more and more useful ancillary tests have become available, which can help distinguish between malignant and benign hepatocellular neoplasms, malignant and benign biliary tract entities, and intrahepatic and metastatic carcinomas. This review will focus on existing and emerging biomarkers (such as glutamine synthetase, organic anion transporting polypeptide 1B3, insulin-like growth factor-II mRNA binding protein-3, S100P, SMAD4, enhancer of zeste homolog 2, albumin, hepatocyte nuclear factor-1β, etc.) that can be used for the diagnosis, classification and prognostication of hepatobiliary neoplasms.

INTRAHEPATIC BILIARY PROLIFERATIONS: HISTOPATHOLOGY AND POTENTIAL IMMUNOHISTOCHEMICAL MARKERS

•Intrahepatic biliary proliferations represent a spectrum varying from reactive to malignant entities. •Clinical and imaging patterns may be similar, requiring histopathological and immunohistochemistry for precise diagnosis. Intrahepatic biliary proliferations represent a spectrum from reactive (ductular reaction, some with atypical architecture), hamartomatous (von Meyenburg complex), benign (bile duct adenoma) and precursor/borderline entities (biliary intraepithelial neoplasia, intraductal papillary neoplasm of the bile duct) to fully malignant (cholangiocarcinoma) neoplasms. Clinical pictures and even imaging patterns may be similar, requiring refined studies aiming at histopathological and immunohistochemistry for more precise diagnosis, essential for correct patient management. This article discusses updated concepts and definitions of most relevant entities aiming more specifically at the differential diagnosis in practice, focusing on morphology and immunohistochemistry, with a discussion of potential markers to help distinguishing between benign and malignant lesions.

Cancerization of ducts in hilar cholangiocarcinoma

Invasive cancers that arise from ductal structures can infiltrate and colonize pre-existing ducts in a process referred to as cancerization of ducts (COD). COD in cholangiocarcinoma is an under-studied process whose clinical significance remains poorly understood. Even though both cancerized ducts and biliary intraepithelial neoplasias (BilINs) show dysplastic changes, hallmarks of COD are (i) an abrupt transition from the normal/reactive epithelium to severe dysplasia and (ii) close proximity to invasive carcinoma with similar cytologic features. We investigated 113 cases of surgically resected hilar cholangiocarcinoma and identified COD in 37 cases (33%). Using immunohistochemistry, we found that COD and adjacent invasive carcinoma had a concordant pattern of p53 and SMAD4 staining in 95% (21/22) and 100% (21/21) of cases, respectively. In contrast, BilINs and cancerized ducts showed significantly lower levels of concordance in p53 and SMAD4 staining at 44% (8/18) and 47% (8/17) of cases, respectively (P = 0.0007 and 0.0001, respectively). By univariate analysis, positive lymph node metastasis (P = 0.027), positive final bile duct margin (P = 0.021), and the presence of COD (P = 0.020) were associated with decreased overall survival. We further performed multivariate analysis to demonstrate that positive lymph node metastasis (P = 0.031), positive final bile duct margin (P = 0.035), and COD (P = 0.0051) were correlated with decreased overall survival. Together, our study highlights that COD is a clinically significant process in hilar cholangiocarcinoma that can be identified using morphological criteria in conjunction with p53 and SMAD4 immunolabeling.

FOXF1 as an Immunohistochemical Marker of Hilar Cholangiocarcinoma or Metastatic Pancreatic Ductal Adenocarcinoma. Single Institution Experience

Cholangiocarcinoma (CCA) is a liver malignancy associated with a poor prognosis. Its main subtypes are peripheral/intrahepatic and hilar/extrahepatic CCA. Several molecular, morphological and clinical similarities between hilar/extrahepatic CCA and pancreatic ductal adenocarcinoma (PDAC) have been described. FOXF1 is a transcription factor which has been described to have prognostic significance in various tumors and it is involved in the development of bile ducts. The aim of this study is to determine occurrence of nuclear expression of FOXF1 in both subtypes of CCA and metastatic PDAC and assess its potential usefulness as a diagnostic marker. Secondary aims were to investigate the use of C-reactive protein (CRP) immunohistochemistry for diagnosing intrahepatic peripheral CCA and the significance of histological features in CCA subtypes. 32 archive specimens of CCA, combined hepatocellular carcinoma-CCA (HCC-CCA) and liver metastasis of PDAC were stained by FOXF1 and CRP immunohistochemistry and evaluated to determine histological pattern. The CCAs were classified radiologically into peripheral/intrahepatic and hilar subtype. Using Fisher exact test, we identified nuclear FOXF1 as a fairly specific (87%) but insensitive (65%) marker of hilar and extrahepatic CCA and metastatic PDAC (p = 0.005). CRP immunohistochemistry was characterized by a high sensitivity and specificity, of 79% and 88%, respectively (p = 0.001). We did not identify any histomorphological features associated with either types of CCA or metastatic PDAC. As a conclusion of novel finding, FOXF1 immunohistochemistry may be regarded as a specific but insensitive marker of hilar/extrahepatic CCA and metastatic PDAC and it may help distinguish them from peripheral CCA.

Clinicopathological significance of olfactomedin-4 in extrahepatic bile duct carcinoma

The clinicopathological and prognostic significance of olfactomedin-4 (OLFM4) expression has not yet been elucidated in extrahepatic bile duct carcinomas (EBDCs). Immunohistochemical analysis of OLFM4 expression in 31 normal biliary epithelia, 33 biliary intraepithelial neoplasias (BilINs), and 180 surgically resected EBDCs (54 perihilar and 126 distal) was performed and was used to analyze clinicopathological variables including patient survival. The expression of OLFM4 showed a progressive increase from normal biliary epithelia (0.2 ± 0.4) to BilINs (2.8 ± 3.2) to EBDCs (4.6 ± 4.2; P < 0.001). OLFM4 was highly expressed in 26.1% (47/180) of the EBDC cases, and high OLFM4 levels were more frequently observed in tumors with nodular growth (P = 0.029), well differentiation (P = 0.011), and lower T-category (P = 0.025) and stage grouping (P = 0.013). Patients with EBDC having high expression of OLFM4 had better survival than those with low expression of OLFM4 (median, 43.3 vs. 29.2 months; P = 0.037). OLFM4 might play an important role in carcinogenesis and in the progression from BilINs to EBDCs. High OLFM4 expression predicted less aggressive clinical behavior in patients with EBDC.

Mucins: the Old, the New and the Promising Factors in Hepatobiliary Carcinogenesis

Mucins are large O-glycoproteins with high carbohydrate content and marked diversity in both the apoprotein and the oligosaccharide moieties. All three mucin types, trans-membrane (e.g., MUC1, MUC4, MUC16), secreted (gel-forming) (e.g., MUC2, MUC5AC, MUC6) and soluble (non-gel-forming) (e.g., MUC7, MUC8, MUC9, MUC20), are critical in maintaining cellular functions, particularly those of epithelial surfaces. Their aberrant expression and/or altered subcellular localization is a factor of tumour growth and apoptosis induced by oxidative stress and several anti-cancer agents. Abnormal expression of mucins was observed in human carcinomas that arise in various gastrointestinal organs. It was widely believed that hepatocellular carcinoma (HCC) does not produce mucins, whereas cholangiocarcinoma (CC) or combined HCC-CC may produce these glycoproteins. However, a growing number of reports shows that mucins can be produced by HCC cells that do not exhibit or are yet to undergo, morphological differentiation to biliary phenotypes. Evaluation of mucin expression levels in precursors and early lesions of CC, as well as other types of primary liver cancer (PLC), conducted in in vitro and in vivo models, allowed to discover the mechanisms of their action, as well as their participation in the most important signalling pathways of liver cystogenesis and carcinogenesis. Analysis of mucin expression in PLC has both basic research and clinical value. Mucins may act as oncogenes and tumour-promoting (e.g., MUC1, MUC13), and/or tumour-suppressing factors (e.g., MUC15). Given their role in promoting PLC progression, both classic (MUC1, MUC2, MUC4, MUC5AC, MUC6) and currently tested mucins (e.g., MUC13, MUC15, MUC16) have been proposed to be important diagnostic and prognostic markers. The purpose of this review was to summarize and update the role of classic and currently tested mucins in pathogenesis of PLC, with explaining the mechanisms of their action in HCC carcinogenesis. It also focuses on determination of the diagnostic and prognostic role of these glycoproteins in PLC, especially focusing on HCC, CC and other hepatic tumours with- and without biliary differentiation.

Cholangiocarcinoma: Classification, Histopathology and Molecular Carcinogenesis

Cholangiocarcinoma (CC) is the second most common tumor of the liver, originating from the biliary system with increasing incidence and mortality worldwide. Several new classifications review the significance of tumor localization, site of origin, proliferation and biomarkers in the intrahepatic, perihilar and distal forms of the lesion. Based on growth pattern mass-forming, periductal-infiltrating, intraductal, undefined and mixed types are differentiated. There are further subclassifications which are applied for the histological features, in particular for intrahepatic CC. Recognition of the precursors and early lesions of CC including biliary intraepithelial neoplasia (BilIN), intraductal papillary neoplasm of the bile ducts (IPNB), biliary mucinous cystic neoplasm (MCNB) and the candidate precursors, such as bile duct adenoma and von Meyenburg complex is of increasing significance. In addition to the previously used biliary markers detected by immunohistochemistry, several new markers have been added to the differentiation of both the benign and malignant lesions, which can be used to aid in the subclassification in association with the outcome of CC. Major aspects of biliary carcinogenesis have been revealed, yet, the exact way of this diverse process is still unclear. The factors contributing to molecular cholangiocarcinogenesis include various risk factors, different anatomical localizations, multiple cellular origins, genetic and epigenetic alterations, tumor microenvironment, heterogeneity and clonal evolution. Driver mutations have been identified, implying that they are optimal candidates for targeted therapy. The most promising therapeutic candidates have entered clinical trials.

Immunohistochemical staining for S100P, SMAD4, and IMP3 on cell block preparations is sensitive and highly specific for pancreatic ductal adenocarcinoma

INTRODUCTION

The diagnosis of pancreatic ductal adenocarcinoma (PDA) on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) material is often challenging. An immunohistochemical (IHC) panel may help establish the diagnosis of PDA in cases limited by sample size or ambiguous cytology. S100P, IMP3, and SMAD4 are 3 IHC markers that have shown promise as individual markers for PDA that have never been tested together as a panel. In this study, we evaluated the individual and combined efficacy of S100P, IMP3, and SMAD4 for the detection of PDA.

MATERIALS AND METHODS

S100P, IMP3, and SMAD4 IHC staining was performed on cell blocks (CBs) procured from pancreatic EUS-FNA procedures. The cohort included CBs that were diagnostic for PDA (n = 35), suspicious but nondiagnostic for PDA (n = 2), as well as CBs with benign pancreatic ductal epithelium (n = 12) and benign reactive pancreatic ductal epithelium (n = 18). A positive result for IMP3 and S100P was defined as moderate or strong staining of >10% of ductal cells. Complete lack of SMAD4 nuclear staining was considered a positive result-any nuclear SMAD4 staining was considered a negative result.

RESULTS

Two and 3 IHC marker panels were almost always more specific than individual IHC markers. Positivity for at least 2 of 3 IHC markers was a sensitive (91.89%) and highly specific (100%) marker of PDA.

CONCLUSIONS

The 3 IHC marker panel composed of S100P, IMP3, and SMAD4 is highly specific for PDA. Future studies should evaluate efficacy in a cohort with more atypical and suspicious cases.

PF-2341066 combined with celecoxib promotes apoptosis and inhibits proliferation in human cholangiocarcinoma QBC939 cells

Intrahepatic cholangiocarcinoma (ICC) is a malignant tumor with high incidence and an average age of onset of 50-70 years old. However, at present there is no effective treatment for this disease. The aim of the present study was to investigate the effects of a c-Met inhibitor, PF-2341066 and a cyclooxygenase-2 (COX-2) inhibitor, celecoxib, on c-Met and COX-2 expression, proliferation and apoptosis. The results demonstrated that c-Met and COX-2 are highly expressed in hepatobiliary calculus with cholangiocarcinoma. PF-2341066 was able to downregulate the expression of c-Met and COX-2 in a dose-dependent manner at the mRNA and protein levels in human cholangiocarcinoma QBC939 cells. Furthermore, combined treatment with PF-2341066 with celecoxib downregulated the mRNA expression of both genes, inhibited cell proliferation and promoted cell apoptosis. It was also demonstrated that PF-2341066 and celecoxib treatment was able to restrict the expression of vascular endothelial growth factor (VEGF). The results of the present study suggest that PF-2341066 and celecoxib may inhibit the development of cholangiocarcinoma by downregulating the expression of c-Met and COX-2 to inhibit cell proliferation, promote apoptosis and prevent VEGF-mediated tumor angiogenesis. Co-treatment with PF-2341066 and celecoxib may be a potential therapeutic strategy for hepatobiliary calculus with cholangiocarcinoma.

Diagnostic Value of S100p, IMP3, Maspin, and pVHL in the Differantial Diagnosis of Pancreatic Ductal Adenocarcinoma and Normal/chronic Pancreatitis in Fine Needle Aspiration Biopsy

Introduction:

Differentiation between pancreatic ductal adenocarcinoma (PDAC) from benign mimickers is a well-known problem in cytological materials. Recent studies incorporated biological markers into this question and some studies showed that expression of S100P, IMP3, and maspin as well as nonexpression of von Hippel-Lindau gene product (pVHL) were significantly correlated with PDAC. In this study, we aimed to investigate diagnostic value of maspin, IMP3, S100P, and pVHL immunostaining in fine needle aspiration biopsies (FNABs) of pancreatic lesions.

Materials and Method:

In all, 33 cases of FNAB cell blocks of PDAC and 34 cases of surgical non-neoplastic pancreas specimens which were retrieved from the archives slides from 2007 to 2011 were included in this study. All the cases were stained with maspin, IMP3, S100P, and pVHL. Expression patterns of markers were scored and compared with benign mimickers. Test performance of each antibody and possible antibody combinations were also evaluated.

Results:

The study was composed of 33 PDAC and 34 control cases (8 chronic pancreatitis, 3 mucinous cystic neoplasm, and 23 nontumoral pancreatic tissue of PDAC). Diagnostic sensitivity for malignancy in S100P, IMP3, and maspin was 84.8%, 81.8%, and 87.5%, respectively. Specificity of these three markers was 100%. Sensitivity and specificity of pVHL for detecting nontumoral pancreatic tissue were 100% and 81.8%, respectively. When maspin, IMP3, and S100P expression were used together as triple test, sensitivity was 62.5% and specificity 100%. However, when any two of each three markers were evaluated (triple test/dual response), sensitivity reached 93.8% and specificity 100%.

Conclusion:

We observed that dual response in triple test (positive staining with two of these three markers) of maspin, IMP3, and S100P immunocytochemistry is very sensitive and specific in differential diagnosis of PDA and non-neoplastic pancreatic lesions. pVHL may have an additional role, when triple assessment is not satisfactory.

Podoplanin is an important stromal prognostic marker in perihilar cholangiocarcinoma

Cancer-associated fibroblasts (CAFs) exhibit various phenotypes and serve an important role in tumor progression. However, research on podoplanin expression in CAFs is limited, and its role in the cholangiocarcinoma microenvironment remains unclear. The present study analyzed the clinical and pathological records of 42 patients diagnosed with perihilar cholangiocarcinoma (pCCA) in The Affiliated Drum Tower Hospital of Nanjing University Medical School (Nanjing, China). Immunohistochemical staining was performed to evaluate the expression of podoplanin in CAFs in order to determine its association with clinicopathological parameters and survival rate. Podoplanin expression in the CAFs was associated with the tumor-node-metastasis staging system, and lymph node metastasis in pCCA. Tumor tissue demonstrated an increase in lymphatic vessel density (LVD) compared with para-tumor tissue. Podoplanin expression in CAFs was associated with LVD in tumor and para-tumor tissues. To examine the effect of podoplanin expression in CAFs on tumor progression, CAFs were isolated from tumor xenografts. Following transfection with an expression plasmid encoding podoplanin, the migratory ability of CAFs was significantly increased. Therefore, CAF-associated podoplanin expression in pCCA may serve as a potential biomarker to evaluate prognosis and provide a valuable target for anticancer therapy.

New insights into cholangiocarcinoma: multiple stems and related cell lineages of origin

Cholangiocarcinoma (CCA) is a heterogeneous group of malignancies that may develop at any level of the biliary tree. CCA is currently classified into intrahepatic (iCCA), perihilar (pCCA) and distal (dCCA) on the basis of its anatomical location. Notably, although these three CCA subtypes have common features, they also have important inter- and intra-tumor differences that can affect their pathogenesis and outcome. A unique feature of CCA is that it manifests in the hepatic parenchyma or large intrahepatic and extrahepatic bile ducts, furnished by two distinct stem cell niches: the canals of Hering and the peribiliary glands, respectively. The complexity of CCA pathogenesis highlights the need for a multidisciplinary, translational, and systemic approach to this malignancy. This review focuses on advances in the knowledge of CCA histomorphology, risk factors, molecular pathogenesis, and subsets of CCA.

Practical Immunohistochemistry in Neoplastic Pathology of the Gastrointestinal Tract, Liver, Biliary Tract, and Pancreas

CONTEXT

- Immunomarkers with diagnostic, therapeutic, or prognostic values have been increasingly used to maximize the benefits of clinical management of patients with neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas.

OBJECTIVES

- To review the characteristics of immunomarkers that are commonly used in surgical pathology practice for neoplasms of the gastrointestinal tract, liver, biliary tract, and pancreas, and to summarize the clinical usefulness of immunomarkers that have been discovered in recent years in these fields.

DATA SOURCES

- Data sources include literature review, authors' research data, and personal practice experience.

CONCLUSIONS

- Immunohistochemistry is an indispensable tool for the accurate diagnosis of neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas. Useful immunomarkers are available to help distinguish malignant neoplasms from benign conditions, determine organ origins, and subclassify neoplasms that are morphologically and biologically heterogeneous. Specific immunomarkers are also available to help guide patient treatment and assess disease aggressiveness, which are keys to the success of personalized medicine. Pathologists will continue to play a critical role in the discovery, validation, and application of new biomarkers, which will ultimately improve patient care.

Annexin A10 optimally differentiates between intrahepatic cholangiocarcinoma and hepatic metastases of pancreatic ductal adenocarcinoma: a comparative study of immunohistochemical markers and panels

Discriminating intrahepatic cholangiocarcinoma (ICC) from hepatic metastases of pancreatic ductal adenocarcinoma (mPDAC) can be challenging. While pathologists might depend on clinical information regarding a primary tumor, their diagnosis will lead the patient either to potentially curative surgery (for ICC) or to palliation (for mPDAC). Beyond the validation of recently published potential biomarkers for PDAC (primary or metastatic) in a large cohort, we assessed diagnostic performance of the most promising candidates in the challenging task of discriminating metastatic PDAC (mPDAC) from ICC. In a training set of 87 ICC and 88 pPDAC, our previously identified biomarkers Annexin A1 (ANXA1), ANXA10, and ANXA13 were tested and compared with 11 published biomarkers or panels (MUCIN 1, Agrin, S100P, MUC5 AC, Laminin, VHL, CK 17, N-Cadherin, ELAC2, PODXL and HSPG2). Biomarkers with best results were further tested in an independent series of biopsies of 27 ICC and 36 mPDAC. Highest AUC values (between 0.72 and 0.84) for the discrimination between ICC and pPDAC were found in the training set for Annexin A1, Annexin A10, MUC5 AC, CK17, and N-Cadherin. These markers were further tested on an independent series of liver biopsies containing ICC or mPDAC. Diagnostic characteristics were evaluated for individual markers as well as for 3× panels. ANXA 10 showed the highest diagnostic potential of all single markers, correctly classifying 75% of mPDAC and 85% of ICC. Our results suggest that ANXA10 may be useful to differentiate between ICC and mPDAC, when only a tissue specimen is available.

Apical membrane expression of distinct sulfated glycans represents a novel marker of cholangiolocellular carcinoma

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver neoplasm, followed by hepatocellular carcinoma. ICC can be further subclassified as (i) perihilar and (ii) peripheral types, the latter histologically resembling small-sized intrahepatic bile ducts, such as interlobular bile ducts, cholangioles/ductules and the canals of Hering. Cholangiolocellular carcinoma (CoCC), now classified by the World Health Organization as a subtype of combined hepatocellular-cholangiocarcinoma, is currently regarded as a subtype of peripheral-type ICC. The present study was undertaken to determine whether sulfated glycans recognized by the MECA-79 monoclonal antibody could serve as a CoCC marker. Using immunohistochemistry, we show that MECA-79 sulfated glycans are preferentially expressed at the apical membrane of cholangiocytes found in small-sized intrahepatic bile ducts in normal liver and in canalicular structures formed in CoCC. We also report that apical membrane MECA-79 sulfated glycan expression colocalizes with that of mucin 1 (MUC1) core proteins. We also present immunoblotting of Chinese hamster ovary cells overexpressing FLAG-tagged MUC1 to show that MUC1 serves as a MECA-79 scaffold. Furthermore, we report that SSP-25 human ICC cells overexpressing N-acetylglucosamine-6-O-sulfotransferase 2 (GlcNAc6ST-2), but not GlcNAc6ST-1, exhibit membrane expression of MECA-79 sulfated glycans, suggesting that GlcNAc6ST-2 catalyzes MECA-79 epitope biosynthesis in cholangiocytes. Moreover, both wild-type and GlcNAc6ST-1 knockout mice exhibit apical membrane MECA-79 expression in small-sized intrahepatic bile ducts, namely interlobular bile ducts, whereas MECA-79 expression was completely absent in comparable tissues from GlcNAc6ST-1 and GlcNAc6ST-2 double knockout mice. These data collectively indicate that apical membrane localization of MUC1 proteins decorated with GlcNAc6ST-2-dependent MECA-79 sulfated glycans may mark cholangiocytes with cholangiolar/ductular differentiation and could serve as a useful CoCC marker.

Immunohistochemical Typing of Adenocarcinomas of the Pancreatobiliary System Improves Diagnosis and Prognostic Stratification

BACKGROUND & AIMS

Adenocarcinomas of the pancreatobiliary system are currently classified by their primary anatomical location. In particular, the pathological diagnosis of intrahepatic cholangiocarcinoma is still considered as a diagnosis of exclusion of metastatic adenocarcinoma. Periampullary cancers have been previously classified according to the histological type of differentiation (pancreatobiliary, intestinal), but overlapping morphological features hinder their differential diagnosis. We performed an integrative immunohistochemical analysis of pancreato-biliary tumors to improve their diagnosis and prediction of outcome.

METHODS

This was a retrospective observational cohort study on patients with adenocarcinoma of the pancreatobiliary system who underwent diagnostic core needle biopsy or surgical resection at a tertiary referral center. 409 tumor samples were analyzed with up to 27 conventional antibodies used in diagnostic pathology. Immunohistochemical scoring system was the percentage of stained tumor cells. Bioinformatic analysis, internal validation, and survival analysis were performed.

RESULTS

Hierarchical clustering and differential expression analysis identified three immunohistochemical tumor types (extrahepatic pancreatobiliary, intestinal, and intrahepatic cholangiocarcinoma) and the discriminant markers between them. Among patients who underwent surgical resection of their primary tumor with curative intent, the intestinal type showed an adjusted hazard ratio of 0.19 for overall survival (95% confidence interval 0.05-0.72; p value = 0.014) compared to the extrahepatic pancreatobiliary type.

CONCLUSIONS

Integrative immunohistochemical classification of adenocarcinomas of the pancreatobiliary system results in a characteristic immunohistochemical profile for intrahepatic cholangiocarcinoma and intestinal type adenocarcinoma, which helps in distinguishing them from metastatic and pancreatobiliary type adenocarcinoma, respectively. A diagnostic immunohistochemical panel and additional extended panels of discriminant markers are proposed as guidance for their pathological diagnosis.

Latest advances in the pathological understanding of cholangiocarcinomas

Cholangiocarcinomas (CCAs) are anatomically classified into intrahepatic, perihilar, and distal types. The gross pathological classification of intrahepatic CCAs divides them into mass-forming, periductal-infiltrating, and intraductal-growth types; and perihilar/distal CCAs into flat- and nodular-infiltrating and papillary types. Unique preinvasive lesions appear to precede individual gross types of CCA. Biliary intraepithelial neoplasia, a flat lesion, precedes periductal-, flat-, and nodular-infiltrating CCAs, whereas intraductal papillary neoplasm of the bile duct (IPNB) precedes the intraductal-growth and papillary type of CCAs. IPNBs are heterogeneous in their histological and pathological profiles along the biliary tree. Hepatobiliary cystadenomas/adenocarcinomas are reclassified as cystic IPNBs and hepatic mucinous cystic neoplasms. Peribiliary glands may participate in the development of CCAs. These latest findings present a new challenge for understanding the pathology of CCAs.

Expert consensus document: Cholangiocarcinoma: current knowledge and future perspectives consensus statement from the European Network for the Study of Cholangiocarcinoma (ENS-CCA)

Cholangiocarcinoma (CCA) is a heterogeneous group of malignancies with features of biliary tract differentiation. CCA is the second most common primary liver tumour and the incidence is increasing worldwide. CCA has high mortality owing to its aggressiveness, late diagnosis and refractory nature. In May 2015, the "European Network for the Study of Cholangiocarcinoma" (ENS-CCA: www.enscca.org or www.cholangiocarcinoma.eu) was created to promote and boost international research collaboration on the study of CCA at basic, translational and clinical level. In this Consensus Statement, we aim to provide valuable information on classifications, pathological features, risk factors, cells of origin, genetic and epigenetic modifications and current therapies available for this cancer. Moreover, future directions on basic and clinical investigations and plans for the ENS-CCA are highlighted.

"Biliary Diseases with Pancreatic Counterparts": Cross-sectional Imaging Findings

On the basis of the similarities in the histopathologic findings and the clinical-biologic behaviors of select biliary and pancreatic conditions, a new disease concept, "biliary diseases with pancreatic counterparts," has been proposed. Both nonneoplastic and neoplastic pathologic conditions of the biliary tract have their counterparts in the pancreas. Immunoglobulin G4 (IgG4)-related sclerosing cholangitis is the biliary manifestation of IgG4-related sclerosing disease, and type 1 autoimmune pancreatitis is its pancreatic counterpart. People with chronic alcoholism can develop peribiliary cysts and fibrosis as well as pancreatic fibrosis and chronic pancreatitis simultaneously. Pancreatic ductal adenocarcinoma, intraductal papillary mucinous neoplasm, and mucinous cystic neoplasm are considered pancreatic counterparts for the biliary neoplasms of extrahepatic cholangiocarcinoma, intraductal papillary neoplasm of the biliary tract, and hepatic mucinous cystic neoplasm, respectively. The anatomic proximity of the biliary tract and the pancreas, the nearly simultaneous development of both organs from the endoderm of the foregut, and the presence of pancreatic exocrine acini within the peribiliary glands surrounding the extrahepatic bile ducts are suggested as causative factors for these similarities. Interestingly, these diseases show "nearly" identical findings at cross-sectional imaging, an observation that further supports this new disease concept. New information obtained with regard to biliary diseases can be used for evaluation of pancreatic abnormalities, and vice versa. In addition, combined genetic and molecular studies may be performed to develop novel therapeutic targets. For both biliary and pancreatic diseases, imaging plays a pivotal role in initial diagnosis, evaluation of treatment response, efficacy testing of novel drugs, and long-term surveillance.

Distal bile duct carcinomas and pancreatic ductal adenocarcinomas: postulating a common tumor entity

The set definition of distal cholangiocarcinomas and adenocarcinomas of the pancreatic head is challenged by their close anatomical relation, similar growth pattern, and corresponding therapeutic outcome. They show a mutual development during embryologic organ formation and share phenotypic characteristics. This review will highlight the similarities with regard to the common origin of their primary organs, histopathological similarities, and modern clinical management. Thus, we propose to subsume those entities under a common superfamily.

Metastasis-associated in colon cancer 1 is an independent prognostic biomarker for survival in Klatskin tumor patients

Curative treatment of intrahepatic cholangiocarcinoma (ICC) and hilar cholangiocarcinoma (Klatskin tumors) is limited to surgical resection or orthotopic liver transplantation. However, not all patients benefit from a surgical approach and suffer from early tumor recurrence. Response to chemotherapy is generally poor and, until today, no targeted therapy could be established. Metastasis-associated in colon cancer 1 (MACC1) is a recently discovered regulator of the hepatocyte growth factor (HGF)/Met/mitogen-activated protein kinase pathway, which induces proliferation, migration, and invasion in cell culture, as well as metastasis in mice. MACC1 expression shows a significant correlation with Met expression in colon cancer tissue and is highly prognostic for occurrence of distant metastasis and survival in colon cancer patients. Thus, we aimed to measure the expression of MACC1, Met, and HGF messenger RNA in microdissected tumor tissue and corresponding normal liver tissue of 156 patients with Klatskin tumors (n = 76) and ICC (n = 80) using real-time quantitative reverse-transcriptase polymerase chain reaction. We used immunohistochemical staining to validate the results. MACC1 expression in tumor tissue of both tumor entities was significantly higher than in corresponding normal liver tissue (P < 0.001). Klatskin tumor patients with a history of tumor recurrence had significantly higher MACC1 expression than those without tumor recurrence (P = 0.005). Uni- und multivariate survival analysis showed that Klatskin tumor patients with high MACC1 had a significantly shorter overall (OS) and disease-free survival (DFS; P = 0.001 and P < 0.001, respectively). The multivariate analysis confirmed MACC1 to be an independent factor for overall survival in Klatskin tumor patients (hazard ratio: 2.777; 95% confidence interval: 1.389-5.555; P = 0.004).

CONCLUSION

Our study identified MACC1 as a highly prognostic biomarker for OS and DFS in Klatskin tumor patients. MACC1 expression could become an important diagnostic tool and might be a candidate for targeted therapy.

Pathologic classification of cholangiocarcinoma: New concepts

Herein, we propose a new pathologic classification of cholangiocarcinoma (CCA) based on recent progress in studies of preinvasive CCA lesions and the relationship of CCA to hepatic progenitor cells, as well as a new concept with respect to the pathologic similarities between biliary and pancreatic neoplasms. Depending on anatomical location, CCA is classifiable as intrahepatic (iCCA), perihilar (pCCA), and distal CCA (dCCA). iCCA is classifiable as the conventional type and the bile ductular type, whereas pCCA and dCCA mainly present as conventional adenocarcinoma. In addition, these three CCAs may present as the intraductal neoplasm type or rare variants. Bile ductular CCA resembles proliferating bile ductules and expressing hepatic progenitor cell phenotypes. Four types of preinvasive lesions are proposed: flat, papillary, tubular lesion, and cystic lesion. These lesions are eventually followed by invasive CCA. Interestingly, these preinvasive lesions have pancreatic counterparts. This CCA classification may introduce a new field of CCA research.

TOP1 gene copy numbers are increased in cancers of the bile duct and pancreas

BACKGROUND

Bile duct and pancreatic cancer (PC) have poor prognoses and treatment options for inoperable patients are scarce. In order to improve outcome for these patients, there is an urgent need for biomarkers predictive of treatment effect. Irinotecan is a topoisomerase 1 (Top1) poison. Top1 protein, TOP1 gene copy number and mRNA expression, respectively, have been proposed as predictive biomarkers of response to irinotecan in other cancers. Here we investigate the occurrence of TOP1 gene aberrations in cancers of the bile ducts and pancreas.

MATERIAL AND METHODS

TOP1 and centromere 20 (CEN-20) numbers were investigated by fluorescence in situ hybridization analyses in tumor tissue from 226 patients. The frequencies of aberration in the TOP1 gene copy number, the CEN-20 copy number and the TOP1/CEN-20 ratio were analyzed. As TOP1 is located on chromosome 20, the CEN-20 probe was included to distinguish between chromosomal and gene amplifications.

RESULTS

In PC, 29.8% had an increased TOP1 copy number (≥ 3.5n gene copies per cell) and 10.8% had a TOP1/CEN-20 ratio >1.5. In bile duct cancer, 12.8 % had an increased TOP1 copy number and 6.4% had a TOP1/CEN-20 ratio >1.5. Neither the TOP1 copy number nor the TOP1/CEN-20 ratios could predict overall survival.

CONCLUSION

We here report that a substantial number of patients with bile duct or PC have increased TOP1 copy number and increased TOP1/CEN-20 ratio making further analyses on the association between TOP1 gene copy number and irinotecan efficacy clinically relevant.

Pancreatic Ductal Adenocarcinoma in a Wistar Hannover GALAS Rat

There are no reported spontaneous cases of pancreatic ductal adenocarcinoma (PDAC), and there are few reports about chemically-induced PDAC in rats. We encountered a PDAC in a Wistar Hannover GALAS rat that had been subjected to a medium-term multiorgan carcinogenicity bioassay. This article describes the histological and histochemical findings of the tumor. The tumor was located in the pancreatic tissue and had not invaded the liver parenchyma or the mucosal layer of the alimentary tract. The tumor cells were atypical and were mainly arranged in small tubules. In addition, abundant stroma and mucus production were observed in the tumor. In an immunohistochemical examination, the tumor cells were positive for cytokeratin, Sox9 and pancreas duodenum homeobox 1 and negative for amylase 2A and insulin. Therefore, the tumor was diagnosed as a PDAC based on its histological and histochemical findings. We considered that the tumor was caused by the carcinogens administered during the abovementioned bioassay.

Morphological subclassification of intrahepatic cholangiocarcinoma: etiological, clinicopathological, and molecular features

On the basis of morphological features, we subclassified 189 intrahepatic cholangiocarcinomas into two subtypes: bile duct and cholangiolar. The cholangiolar type is composed of cuboidal to low columnar tumor cells that contain scanty cytoplasm. The bile duct type is composed of tall columnar tumor cells arranged in a large glandular pattern. In this study, 77 (41%) tumors were classified as the cholangiolar type and 112 (59%) tumors were classified as the bile duct type. The cholangiolar-type intrahepatic cholangiocarcinoma was more frequently associated with viral hepatitis, whereas all but one intrahepatic cholangiocarcinoma associated with intrahepatic lithiasis were classified as the bile duct type. Biliary intraepithelial neoplasm or intraductal papillary neoplasm of the bile duct could be identified in 50 bile duct-type intrahepatic cholangiocarcinomas (45%), but in only 3 cholangiolar-type intrahepatic cholangiocarcinomas (4%). Cholangiolar-type intrahepatic cholangiocarcinomas frequently expressed N-cadherin, whereas bile duct intrahepatic cholangiocarcinomas were more likely to express S100P, Trefoil factor 1, and anterior gradient 2. KRAS is mutated in 23 of 98 (23%) bile duct-type intrahepatic cholangiocarcinomas and in only 1 of 76 (1%) cholangiolar-type intrahepatic cholangiocarcinomas. Cholangiolar-type intrahepatic cholangiocarcinomas had a higher frequency of IDH1 or 2 mutations than did the bile duct-type intrahepatic cholangiocarcinomas. The molecular features of the bile duct-type intrahepatic cholangiocarcinoma were similar to those of hilar cholangiocarcinoma. Patients with the cholangiolar-type intrahepatic cholangiocarcinoma had higher 5-year survival rates than those of patients with the bile duct-type intrahepatic cholangiocarcinoma. Our results indicated that intrahepatic cholangiocarcinoma was a heterogeneous tumor. Subclassification of intrahepatic cholangiocarcinomas based on cholangiocytic differentiation divides them into two groups with different etiologies, clinical manifestations, and molecular pathogeneses.

Evaluation of contemporary prostate and urothelial lineage biomarkers in a consecutive cohort of poorly differentiated bladder neck carcinomas

OBJECTIVES

New immunohistochemical (IHC) markers of urothelial carcinoma (UCa) and prostatic adenocarcinoma (PCa) have emerged in recent years, yet comparative studies to establish markers remain lacking. We aimed to identify an effective but parsimonious approach for poorly differentiated bladder neck lesions, to establish a best practice panel approach in a setting simulating prospective use.

METHODS

We tested the performance of a panel of IHC markers on whole sections of a consecutive cohort of transurethral resection specimens of poorly differentiated, challenging bladder neck resections (n=36).

RESULTS

In the setting of poorly differentiated bladder neck carcinomas, biomarker sensitivities for UCa were as follows: GATA3, 100%; S100P, 88%; p63, 75%; and cytokeratin (CK) 5/6, 56%; specificities of each were 100%. CK7 and CK20 showed sensitivities of 75% and 63%, though these were only 85% and 80% specific. For PCa markers, NKX3.1, p501S, prostate-specific membrane antigen, and androgen receptor (AR) each showed 100% sensitivity, outperforming ERG (35%) and prostate-specific antigen (PSA; 25%). All the prostate histogenesis markers were 100% specific, except for AR, which was positive in 13% of the UCa cases.

CONCLUSIONS

Novel IHC markers show improved diagnostic performance that enables positive and negative support for identifying histogenesis with the use of as few as two markers for this critical therapeutic distinction. PSA underperforms newer markers.

Prognostic significance of epithelial-mesenchymal transition-related markers in extrahepatic cholangiocarcinoma: comprehensive immunohistochemical study using a tissue microarray

Background:

Epithelial–mesenchymal transition (EMT) is characterised by the loss of cell-to-cell adhesion and gaining of mesenchymal phenotypes. Epithelial–mesenchymal transition is proposed to occur in various developmental processes and cancer progression. ‘Cadherin switch', a process in which cells shift to express different isoforms of the cadherin transmembrane protein and usually refers to a switch from the expression of E-cadherin to N-cadherin, is one aspect of EMT and can have a profound effect on tumour invasion/metastasis. The aim of this study was to investigate the clinicopathological significance of EMT-related proteins and cadherin switch in extrahepatic cholangiocarcinoma (EHCC).

Methods:

We investigated the association between altered expression of 12 EMT-related proteins and clinical outcomes in patients with EHCC (n=117) using immunohistochemistry on tissue microarrays.

Results:

Univariate and multivariate analyses revealed that, in addition to N classification (P=0.0420), the expression of E-cadherin (P=0.0208), N-cadherin (P=0.0038) and S100A4 (P=0.0157) was each an independent and a significant prognostic factor. We also demonstrated that cadherin switch was independently associated with poor prognosis (P=0.0143) in patients with EHCC.

Conclusions:

These results may provide novel information for selection of patients with EHCC who require adjuvant therapy and strict surveillance.

Hilar cholangiocarcinoma is pathologically similar to pancreatic duct adenocarcinoma: suggestions of similar background and development

Routine experiences suggest that cholangiocarcinomas (CCAs) show different clinicopathological behaviors along the biliary tree, and hilar CCA apparently resembles pancreatic duct adenocarcinoma (PDAC). Herein, the backgrounds for these similarities were reviewed. While all cases of PDAC, hilar CCA, intrahepatic CCA (ICCA) and CCA components of combined hepatocellular-cholangiocarcinoma (cHC-CCA) were adenocarcinomas, micropapillary patterns and columnar carcinoma cells were common in PDAC and hilar CCA, and trabecular components and cuboidal carcinoma cells were common in ICCA and CCA components of cHC-CCA. Anterior gradient protein-2 and S100P were frequently expressed in perihilar CCA and PDAC, while neural cell adhesion molecule and luminal epithelial membrane antigen were common in CCA components of c-HC-CCA. Pdx1 and Hes1 were frequently and markedly expressed aberrantly in PDAC and perihilar CCA, although their expression was rare and mild in CCA components in cHC-CCA and ICCA. Hilar CCA showed a similar postoperative prognosis to PDAC but differed from ICCA and cHC-CCA. Taken together, hilar CCA may differ from ICCA and CCA components of cHC-CCA but have a similar development to PDAC. These similarities may be explained by the unique anatomical, embryological and reactive nature of the pancreatobiliary tract. Further studies of these intractable malignancies are warranted.

Pathological diagnosis of flat epithelial lesions of the biliary tract with emphasis on biliary intraepithelial neoplasia

Flat epithelial lesions of the biliary tract cannot be detected by the image analysis, and the diagnosis entirely depends on pathological examination. The biliary tract is often affected by inflammatory conditions, and the resultant changes of the biliary epithelium make it difficult to differentiate them from neoplasia. Thus, the pathological diagnosis of biliary flat epithelial lesions can be challenging. In the biliary tract, there are several forms of intraepithelial neoplasia of the flat type, and biliary intraepithelial neoplasia (BilIN) is known as one of such lesions that represent the multistep cholangiocarcinogenesis. In this article, the diagnostic criteria and the differential diagnosis of biliary flat epithelial lesions, particularly focusing on BilIN, were presented and discussed to provide help to advance clinical and research applications of the BilIN system.

Histological Characterization of Biliary Intraepithelial Neoplasia with respect to Pancreatic Intraepithelial Neoplasia

Biliary intraepithelial neoplasia (BilIN) is a precursor lesion of hilar/perihilar and extrahepatic cholangiocarcinoma. BilIN represents the process of multistep cholangiocarcinogenesis and is the biliary counterpart of pancreatic intraepithelial neoplasia (PanIN). This study was performed to clarify the histological characteristics of BilIN in relation to PanIN. Using paraffin-embedded tissue sections of surgically resected specimens of cholangiocarcinoma associated with BilIN and pancreatic ductal adenocarcinoma associated with PanIN, immunohistochemical staining was performed using primary antibodies against MUC1, MUC2, MUC5AC, cyclin D1, p21, p53, and S100P. For mucin staining, Alcian blue pH 2.5 was used. Most of the molecules examined here showed similar expression patterns in BilIN and PanIN, in which their expression tended to increase along with the increase in atypia of the epithelial lesions. Significant differences were observed in the increase in mucin production and the expression of S100P in PanIN-1 and the expression of p53 in PanIN-3, when compared with those in BilIN of a corresponding grade. These results suggest that cholangiocarcinoma and pancreatic ductal adenocarcinoma share, at least in part, a common carcinogenic process and further confirm that BilIN can be regarded as the biliary counterpart of PanIN.

What are the precursor and early lesions of peripheral intrahepatic cholangiocarcinoma?

Cholangiocarcinoma (CC) is divided into distal, perihilar, and intrahepatic CCs (ICCS), and are further subdivided into large bile duct ICC and peripheral ICC. In distal and perihilar CC and large duct ICC, biliary intraepithelial neoplasm (BilIN) and intraductal papillary neoplasm (IPN) have been proposed as precursor lesions. Peripheral ICC, bile duct adenoma (BDA), biliary adenofibroma (BAF), and von Meyenburg complexes (VMCs) are reportedly followed by development of ICCs. Herein, we surveyed these candidate precursor lesions in the background liver of 37 cases of peripheral ICC and controls (perihilar CC, 34 cases; hepatocellular carcinoma, 34 cases and combined hepatocellular cholangiocarcinoma, 25 cases). In the background liver of peripheral ICC, BDA and BAF were not found, but there were not infrequently foci of BDA-like lesions and atypical bile duct lesions involving small bile ducts (32.4% and 10.8%, resp.). VMCs were equally found in peripheral CCs and also control CCs. In conclusion, BDA, BAF, and VMCs are a possible precursor lesion of a minority of peripheral CCs, and BDA-like lesions and atypical bile duct lesions involving small bile ducts may also be related to the development of peripheral ICC. Further pathologic studies on these lesions are warranted for analysis of development of peripheral ICCs.

Participation of peribiliary glands in biliary tract pathophysiologies

AIM: To investigate the roles of peribiliary glands around the bile ducts in the pathophysiology of the biliary tract.

METHODS: The expression of fetal pancreatic markers, pancreatic duodenal homeobox factor 1 (PDX1) and hairy and enhancer of split 1 (HES1) and endodermal stem/progenitor (S/P) cell markers [CD44s, chemokine receptor type 4 (CXCR4), SOX9 and epithelial cell adhesion molecule (EpCAM)] were examined immunohistochemically in 32 normal adult livers (autopsy livers) and 22 hepatolithiatic livers (surgically resected livers). The latter was characterized by the proliferation of the peribiliary glands. Immunohistochemistry was performed using formalin-fixed, paraffin-embedded tissue sections after deparaffinization. Although PDX1 and HES1 were expressed in both the nucleus and cytoplasm of epithelial cells, only nuclear staining was evaluated. SOX9 was expressed in the nucleus, while CD44s, CXCR4 and EpCAM were expressed in the cell membranes. The frequency and extent of the expression of these molecules in the lining epithelia and peribiliary glands were evaluated semi-quantitatively based on the percentage of positive cells: 0, 1+ (focal), 2+ (moderate) and 3+ (extensive).

RESULTS: In normal livers, PDX1 was infrequently expressed in the lining epithelia, but was frequently expressed in the peribiliary glands. In contrast, HES1 was frequently expressed in the lining epithelia, but its expression in the peribiliary glands was focal, suggesting that the peribiliary glands retain the potential of differentiation toward the pancreas and the lining epithelia exhibit properties to inhibit such differentiation. This unique combination was also seen in hepatolithiatic livers. The expression of endodermal S/P cell markers varied in the peribiliary glands in normal livers: SOX9 and EpCAM were frequently expressed, CD44s infrequently, and CXCR4 almost not at all. The expression of these markers, particularly CD44s and CXCR4, increased in the peribiliary glands and lining epithelia in hepatolithiatic livers. This increased expression of endodermal S/P cell markers may be related to the increased production of intestinal and gastric mucin and also to the biliary neoplasia associated with the gastric and intestinal phenotypes reported in hepatolithiasis.

CONCLUSION: The unique expression pattern of PDX1 and HES1 and increased expression of endodermal S/P cell markers in the peribiliary glands may be involved in biliary pathophysiologies.