Expression of cell cycle-related molecules in biliary premalignant lesions: biliary intraepithelial neoplasia and biliary intraductal papillary neoplasm

Dysplasia and Early Carcinoma of the Gallbladder and Bile Ducts: Terminology, Classification, and Significance

Most precursor lesions and early cancerous changes in the gallbladder and bile ducts present as clinically/grossly inapparent lesions. Low-grade dysplasia is difficult to define and clinically inconsequential by itself; however, extra sampling is required to exclude accompanying significant lesions. For high-grade dysplasia ('carcinoma in situ'), a complete sampling is necessary to rule out invasion. Tumoral intramucosal neoplasms (ie, intracholecystic and intraductal neoplasia) form radiologically/grossly visible masses, and they account for (present in the background of) about 5% to 10% of invasive cancers of the region. These reveal a spectrum of papilla/tubule formation, cell lineages, and dysplastic transformation. Some subtypes such as intracholecystic tubular non-mucinous neoplasm of the gallbladder (almost never invasive) and intraductal oncocytic or intraductal tubulopapillary neoplasms of the bile ducts (may have a protracted clinical course even when invasive) are to be noted separately. Other types of intracholecystic/intraductal neoplasia have a high frequency of invasive carcinoma and progressive behavior, which often culminates in mortality.

Biliary Tract Cancer: Molecular Biology of Precursor Lesions

Biliary tract cancer is a devastating malignancy of the bile ducts and gallbladder with a dismal prognosis. The study of precancerous lesions has received considerable attention and led to a histopathological classification which, in some respects, remains an evolving field. Consequently, increasing efforts have been devoted to characterizing the molecular pathogenesis of the precursor lesions, with the aim of better understanding the mechanisms of tumor progression, and with the ultimate goal of meeting the challenges of early diagnosis and treatment. This review delves into the molecular mechanisms that initiate and promote the development of precursor lesions of intra- and extrahepatic cholangiocarcinoma and of gallbladder carcinoma. It addresses the genomic, epigenomic, and transcriptomic landscape of these precursors and provides an overview of animal and organoid models used to study them. In conclusion, this review summarizes the known molecular features of precancerous lesions in biliary tract cancer and highlights our fragmentary knowledge of the molecular pathogenesis of tumor initiation.

Intraductal neoplasms of the pancreatobiliary tract: navigating the alphabet

Cancers of the pancreatobiliary tract are diseases with unfavourable prognoses. In the last couple of decades, two types of lesions have been described as precursors that precede pancreatobiliary cancers. These include incidental microscopic (flat) lesions known as pancreatic intra-epithelial neoplasia and biliary intra-epithelial neoplasia, and grossly visible, mass-forming lesions (tumoral intra-epithelial neoplasia) including intraductal papillary mucinous neoplasms, intraductal oncocytic papillary neoplasms, intraductal tubulopapillary neoplasms, intraductal papillary neoplasms of the bile duct and intracholecystic papillary neoplasms. Early detection and adequate treatment of these precursor lesions, especially the second group, have the potential to prevent pancreatobiliary cancer or at least improve its prognosis. In this review, we discuss their histopathology and recent updates on molecular profiling of these intraductal neoplasms of the pancreatobiliary tract.

Bile duct dysplasia and associated invasive carcinoma: clinicopathological features, diagnosis, and practical challenges

Cholangiocarcinoma represents the second most frequent type of primary liver cancer that develops through a multistep histopathologic sequence. Dysplasia in the biliary tract epithelium is a precursor lesion of cholangiocarcinoma. This review provides a practical overview of bile duct dysplasia in relation to invasive carcinoma, covering clinicopathological features, diagnostic criteria, differential diagnosis, useful testing modalities, and challenges in daily practice. The key features of biliary intraepithelial neoplasia, intraductal papillary neoplasm, intraductal tubulopapillary neoplasm, and mucinous cystic neoplasm are described. Important differential diagnoses are included. Common pitfalls in histopathologic interpretation of bile duct biopsies and frozen sections are discussed.

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.

Concurrent Activation of Kras and Canonical Wnt Signaling Induces Premalignant Lesions That Progress to Extrahepatic Biliary Cancer in Mice

Biliary cancer has long been known to carry a poor prognosis, yet the molecular pathogenesis of carcinoma of the extrahepatic biliary system and its precursor lesions remains elusive. Here we investigated the role of Kras and canonical Wnt pathways in the tumorigenesis of the extrahepatic bile duct (EHBD) and gall bladder (GB). In mice, concurrent activation of Kras and Wnt pathways induced biliary neoplasms that resembled human intracholecystic papillary-tubular neoplasm (ICPN) and biliary intraepithelial neoplasia (BilIN), putative precursors to invasive biliary cancer. At a low frequency, these lesions progressed to adenocarcinoma in a xenograft model, establishing them as precancerous lesions. Global gene expression analysis revealed increased expression of genes associated with c-Myc and TGFβ pathways in mutant biliary spheroids. Silencing or pharmacologic inhibition of c-Myc suppressed proliferation of mutant biliary spheroids, whereas silencing of Smad4/Tgfbr2 or pharmacologic inhibition of TGFβ signaling increased proliferation of mutant biliary spheroids and cancer formation in vivo. Human ICPNs displayed activated Kras and Wnt signals and c-Myc and TGFβ pathways. Thus, these data provide direct evidence that concurrent activation of the Kras and canonical Wnt pathways results in formation of ICPN and BilIN, which could develop into biliary cancer.

SIGNIFICANCE

This work shows how dysregulation of canonical cell growth pathways drives precursors to biliary cancers and identifies several molecular vulnerabilities as potential therapeutic targets in these precursors to prevent oncogenic progression.

Up-to-Date Pathologic Classification and Molecular Characteristics of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is an aggressive primary liver malignancy with an increasing incidence worldwide. Recently, histopathologic classification of small duct type and large duct type iCCA has been introduced. Both these types of tumors exhibit differences in clinicopathological features, mutational profiles, and prognosis. Small duct type iCCA is composed of non-mucin-producing cuboidal cells, whereas large duct type iCCA is composed of mucin-producing columnar cells, reflecting different cells of origin. Large duct type iCCA shows more invasive growth and poorer prognosis than small duct type iCCA. The background liver of small duct type iCCA often shows chronic liver disease related to hepatitis B or C viral infection, or alcoholic or non-alcoholic fatty liver disease/steatohepatitis, in contrast to large duct type iCCA that is often related to hepatolithiasis and liver fluke infection. Cholangiolocarcinoma is a variant of small duct type iCCA composed of naïve-looking cuboidal cells forming cords or ductule-like structures, and shows better prognosis than the conventional small duct type. Fibrous tumor stroma, one of the characteristic features of iCCA, contains activated fibroblasts intermixed with innate and adaptive immune cells. The types of stroma (mature versus immature) are related to tumor behavior and prognosis. Low tumor-infiltrating lymphocyte density, KRAS alteration, and chromosomal instability are related to immune-suppressive tumor microenvironments with resistance to programmed death 1/ programmed death ligand 1 blockade. Data from recent large-scale exome analyses have revealed the heterogeneity in the molecular profiles of iCCA, showing that small duct type iCCA exhibit frequent BAP1, IDH1/2 hotspot mutations and FGFR2 fusion, in contrast to frequent mutations in KRAS, TP53, and SMAD4 observed in large duct type iCCA. Multi-omics analyses have proposed several molecular classifications of iCCA, including inflammation class and proliferation class. The inflammation class is enriched in inflammatory signaling pathways and expression of cytokines, while the proliferation class has activated oncogenic growth signaling pathways. Diverse pathologic features of iCCA and its associated multi-omics characteristics are currently under active investigation, thereby providing insights into precision therapeutics for patients with iCCA. This review provides the latest knowledge on the histopathologic classification of iCCA and its associated molecular features, ranging from tumor microenvironment to genomic and transcriptomic research.

Recent Advances in Digestive Tract Tumors: Updates From the 5th Edition of the World Health Organization "Blue Book"

CONTEXT.—

The World Health Organization Classification of Tumours: Digestive System Tumors, 5th edition, was published in 2019 and shows several impactful changes as compared with the 4th edition published in 2010. Changes include a revised nomenclature of serrated lesions and revamping the classification of neuroendocrine neoplasms. Appendiceal goblet cell adenocarcinoma is heavily revised, and intrahepatic cholangiocarcinoma is split into 2 subtypes. New subtypes of colorectal carcinoma and hepatocellular carcinoma are described. Precursor lesions are emphasized with their own entries, and both dysplastic and invasive lesions are generally recommended to be graded using a 2-tier system. Hematolymphoid tumors, mesenchymal tumors, and genetic tumor syndromes each have their own sections in the 5th edition. New hematolymphoid lesions include monomorphic epitheliotropic intestinal T-cell lymphoma; duodenal-type follicular lymphoma; intestinal T-cell lymphoma, not otherwise specified; and indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. This paper will provide an in-depth look at the changes in the 5th edition as compared with the 4th edition.

OBJECTIVE.—

To provide a comprehensive, in-depth update on the World Health Organization classification of digestive tumors, including changes to nomenclature, updated diagnostic criteria, and newly described entities.

DATA SOURCES.—

The 5th edition of the World Health Organization Classification of Tumours: Digestive System Tumours, as well as the 4th edition.

CONCLUSIONS.—

The World Health Organization has made many key changes in its newest update on tumors of the digestive system. Pathologists should be aware of these changes and incorporate them into their practice as able or necessary.

Cystic biliary tumors of the liver: diagnostic criteria and common pitfalls

With major advancements and frequent use of abdominal imaging techniques, hepatic cysts are increasingly encountered in clinical practice. Although the majority of cysts are benign, a small subset represents neoplastic precursors to cholangiocarcinoma. These cystic precursors include intraductal papillary neoplasms of the bile duct (IPNB) and mucinous cystic neoplasms of the liver (MCN-L), and bear striking pathologic resemblance to corresponding cystic neoplastic precursors within the pancreas. This review examines the salient clinical, gross, microscopic and molecular features of IPNBs and MCN-Ls, and, in particular, provides histopathologic comparison to their pancreatic counterparts. Considering these neoplasms may be diagnostically challenging, we also discuss other hepatic lesions within the differential diagnosis, and the potential for molecular methods to improve their preoperative evaluation and the early detection of cholangiocarcinoma.

Intraductal Papillary Neoplasm of Bile Duct: Updated Clinicopathological Characteristics and Molecular and Genetic Alterations

Intraductal papillary neoplasm of the bile duct (IPNB), a pre-invasive neoplasm of the bile duct, is being established pathologically as a precursor lesion of invasive cholangiocarcinoma (CCA), and at the time of surgical resection, approximately half of IPNBs show stromal invasion (IPNB associated with invasive carcinoma). IPNB can involve any part of the biliary tree. IPNB shows grossly visible, exophytic growth in a dilated bile duct lumen, with histologically villous/papillary neoplastic epithelia with tubular components covering fine fibrovascular stalks. Interestingly, IPNB can be classified into four subtypes (intestinal, gastric, pancreatobiliary and oncocytic), similar to intraductal papillary mucinous neoplasm of the pancreas (IPMN). IPNBs are classified into low-grade and high-grade based on lining epithelial features. The new subclassification of IPNB into types 1 (low-grade dysplasia and high-grade dysplasia with regular architecture) and 2 (high-grade dysplasia with irregular architecture) proposed by the Japan–Korea pathologist group may be useful in the clinical field. The outcome of post-operative IPNBs is more favorable in type 1 than type 2. Recent genetic studies using next-generation sequencing have demonstrated the existence of several groups of mutations of genes: (i) IPNB showing mutations in KRAS, GNAS and RNF43 belonged to type 1, particularly the intestinal subtype, similar to the mutation patterns of IPMN; (ii) IPNB showing mutations in CTNNB1 and lacking mutations in KRAS, GNAS and RNF43 belonged to the pancreatobiliary subtype but differed from IPMN. IPNB showing mutation of TP53, SMAD4 and PIK3CA might reflect complicated and other features characterizing type 2. The recent recognition of IPNBs may facilitate further clinical and basic studies of CCA with respect to the pre-invasive and early invasive stages.

Latest evidence on immunotherapy for cholangiocarcinoma

Cholangiocarcinoma (CCA) is a type of aggressive tumor that involves the intrahepatic, perihilar and distal biliary tree, and is usually diagnosed at an advanced stage. The standard first-line systemic therapy for patients with advanced CCA is a combination of gemcitabine and cisplatin; targeted therapies and angiogenesis inhibitors are not widely used clinically at present. However, with the development of precision medicine, immunotherapy has started to play a more important role. Programmed cell death protein 1 inhibitors are now considered a good therapeutic option for CCA. Treatments using chimeric antigen receptor T cells, bispecific antibodies, oncolytic viruses and cancer vaccines have also achieved satisfactory results. In addition, combinations of immunotherapy with a variety of conventional therapies have shown some efficacy, and several studies have provided insights into their use in antitumor therapy. Although there are numerous challenges in the treatment of advanced CCA, immunotherapy remains a noteworthy breakthrough. The current evidence on the immunotherapy of CCA is discussed in the present review.

Synchronous Double Bile Duct Cancers with Distinct Genetic Features

A 69-year-old man was referred to our hospital because of appetite loss. Imaging showed a nodular tumor in the perihilar bile duct and a second flat lesion in the distal bile duct. Right hepatopancreaticoduodenectomy was performed, and the histopathological findings demonstrated that the perihilar and distal lesions were moderately and poorly differentiated adenocarcinoma, respectively, and anatomically separated. Furthermore, the resected specimens showed no pancreaticobiliary maljunction. Histological and TP53 gene analyses in a rare case of synchronous double bile duct cancers suggest that there are various genetic pathways through which bile duct cancer develops, highlighting the complexity of its pathogenesis.

Multifocal origin of occupational cholangiocarcinoma revealed by comparison of multilesion mutational profiles

Recently identified occupational cholangiocarcinoma among printing workers is characterized by chronic bile duct injuries and precancerous or early cancerous lesions at multiple sites of the bile ducts. These observations suggested the potential multifocal carcinogenesis of the disease. We performed whole-exome analysis of multiple lesions, including the invasive carcinomas and precancerous lesions of four occupational cholangiocarcinoma cases. A much higher mutation burden was observed in both the invasive carcinomas (mean 76.3/Mb) and precancerous lesions (mean 71.8/Mb) than in non-occupational cholangiocarcinomas (mean 1.6/Mb). Most somatic mutations identified in 11 of 16 lesions did not overlap with each other. In contrast, a unique trinucleotide mutational signature of GpCpY to GpTpY was shared among the lesions. These results suggest that most of these lesions are multiclonal in origin and that common mutagenic processes, which may be induced by exposure to haloalkanes or their metabolites, generated somatic mutations at different sites of the bile ducts. A similarly high mutation rate had already been identified in the precancerous lesions, implying an increased potential for carcinogenesis throughout the biliary tree. These genomic features support the importance of ongoing close follow-up of the patients as a group at high risk of recurrence.

Clinicopathologic analysis of intraductal papillary neoplasm of bile duct: Korean multicenter cohort study

BACKGROUND

IPNB is very rare disease and most previous studies on IPNB were case series with a small number due to low incidence. The aim of this study is to validate previously known clinicopathologic features of intraductal papillary neoplasm of bile duct (IPNB) based on the first largest multicenter cohort.

METHODS

Among 587 patients previously diagnosed with IPNB and similar diseases from each center in Korea, 387 were included in this study after central pathologic review. We also reviewed all preoperative image data.

RESULTS

Of 387 patients, 176 (45.5%) had invasive carcinoma and 21 (6.0%) lymph node metastasis. The 5-year overall survival was 80.9% for all patients, 88.8% for IPNB with mucosal dysplasia, and 70.5% for IPNB with invasive carcinoma. According to the "Jang & Kim's modified anatomical classification," 265 (68.5%) were intrahepatic, 103 (26.6%) extrahepatic, and 16 (4.1%) diffuse type. Multivariate analysis revealed that tumor invasiveness was a unique predictor for survival analysis. (p = 0.047 [hazard ratio = 2.116, 95% confidence interval 1.010-4.433]).

CONCLUSIONS

This is the first Korean multicenter study on IPNB through central pathologic and radiologic review process. Although IPNB showed good long-term prognosis, relatively aggressive features were also found in invasive carcinoma and extrahepatic/diffuse type.

Precursor Lesions of Cholangiocarcinoma: A Clinicopathologic Review

Cholangiocarcinoma (CCA) develops through multistep carcinogenesis. During the past decades, 2 precursors have been proved to evolve to CCA. The 2 main precursor lesions of CCA are biliary intraepithelial neoplasia and intraductal papillary neoplasm of the bile duct. It is an interesting and relatively novel entity for the hepatobiliary surgeons, radiologists, oncologists, and pathologists. It worth being familiar with these 2 entities for better communication between pathologists, oncologists, and surgeons to improve the treatment and follow-up of these lesions, which can definitely decrease their evolvement to CCA as an aggressive, poor prognostic, and life-threatening cancer. In this narrative review, I collected and discussed all published studies about these 2 precursor lesions of CCA including radiologic, clinical, and pathological manifestation.

Genetically engineered animal models of biliary tract cancers

PURPOSE OF REVIEW

Biliary tract cancers which include intrahepatic and extrahepatic cholangiocarcinomas and gallbladder cancer, are characterized by poor outcome. Therefore, identifying the molecular mechanisms of the disease has become a priority. However, such identification has to cope with extreme heterogeneity of the disease, which results from the variable anatomical location, the numerous cell types of origin and the high number of known genetic alterations.

RECENT FINDINGS

Animal models can develop invasive and metastatic tumours that recapitulate as faithfully as possible the molecular features of the human tumours. To generate animal models of cholangiocarcinoma, investigators resorted to the administration of carcinogens, induction of cholestasis, grafting of tumour cells and induction of genetic modifications.

SUMMARY

Here, we summarize the currently available genetically engineered animal models, and focus on mice and zebrafish. The experimental strategies that were selected to induce cholangiocarcinoma in a time-controlled and cell-type-specific manner are critically examined. We discuss their strengths and limitations while considering their relevance to human pathophysiology.

A rare case of symptomatic grossly-visible biliary intraepithelial neoplasia mimicking cholangiocarcinoma

Background

Biliary intraepithelial neoplasia (BilIN) is often distinguished by what it is not: the precancerous lesions are not mass-forming, are not the cause of bile duct obstruction, and are small enough (less than 5 mm long) to evade detection by the naked eye. Here, we describe an atypical case of BilIN resembling cholangiocarcinoma (CC) that was large enough to be identified by diagnostic imaging and presented with obstructive jaundice caused by a hematoma in the common bile duct (CBD).

Case presentation

A 64-year-old man presented to our hospital with upper abdominal pain and anorexia. Initial laboratory examinations revealed increased total bilirubin and a computed tomography (CT) scan revealed a dilated CBD. Gastroenterologists performed an endoscopic sphincterotomy (EST), which revealed that the cause of obstructive jaundice was a hematoma in the CBD. Enhanced CT scan and magnetic resonance cholangiopancreatography (MRCP) performed after the hematoma was drained showed improved dilation of the CBD and an enhanced wall thickness of bile duct measuring 25 × 10 mm at the union of the cystic and common hepatic ducts. A cholangioscope detected an elevated tumor covered by sludge in the CBD, and we performed an extrahepatic bile duct resection and cholecystectomy. The postoperative course was uneventful and the pathological examination of the resected tumor revealed that although the ulcerated lesion had inflammatory granulation tissue, it did not contain the components of invasive carcinoma. Many consecutive intraepithelial micropapillary lesions spread around the ulcerated lesion, and the epithelial cells showed an increased nucleus-to-cytoplasm ratio, nuclear hyperchromasia, and architectural atypia. The pathological diagnosis was BilIN-1 to -2. Immunohistochemical staining showed that S100P was slightly expressed and MUC5AC was positive, while MUC1 was negative and p53 was not overexpressed.

Conclusion

We experienced an atypical case of BilIN mimicking CC that presented with obstructive jaundice caused by a hematoma in the CBD. Our case suggested that the occurrence of BilIN can be triggered by factors other than inflammation, and can grow to a size large enough to be detected by image analyses.

CK20 and lymph node involvement predict adverse outcome of malignant intraductal papillary neoplasm of the bile duct

OBJECTIVES

To identify prognostic factors of malignant intraductal papillary neoplasm of the bile duct (m-IPNB).

MATERIALS AND METHODS

We included 38 consecutive cases which underwent surgical resection and diagnosed as IPNB with malignant component from January 2003 to January 2017. Clinicopathological variables were collected to conduct survival analysis and identify prognostic factors.

RESULTS

The median overall survival (OS) of m-IPNB was 76.0 months, with 1-, 3-, and 5-year survival rates of 97.2%, 73.5%, and 59.8%, respectively. The median RFS was 48.0 months with 1-, 3-, and 5-year recurrence-free survival (RFS) rate was 83.2%, 59.8%, and 44.6%, respectively. Univariate analysis showed that elevation of carcinoembryonic antigen CEA, lymph node involvement, resection margin status, degree of periductal invasion, and positive expression of CK20 were associated with both OS and RFS of m-IPNB. After multivariate Cox models analysis, lymph node involvement and positive expression of CK20 were identified as independent prognostic factors for OS, while lymph node involvement and resection margin status were independent prognostic factors for RFS. The median OS of patients with m-IPNB involving lymphatic metastases and positive expression of CK20 was 27.0±8.8 months and 51.0±12.4 months, respectively. The median RFS of cases with lymph node involvement and R1 resection was 10.0±3.3 months and 25.0±6.9 months, respectively. However, there was no significant difference in OS or RFS between cases of pancreaticobiliary and intestinal subtype.

CONCLUSIONS

Lymph node involvement and positive expression of CK20 are independent prognostic factors for shorter OS of m-IPNB, while patients with lymph node involvement and positive resection margin are at higher risk of tumor recurrence.

Common features between neoplastic and preneoplastic lesions of the biliary tract and the pancreas

the bile duct system and pancreas show many similarities due to their anatomical proximity and common embryological origin. Consequently, preneoplastic and neoplastic lesions of the bile duct and pancreas share analogies in terms of molecular, histological and pathophysiological features. Intraepithelial neoplasms are reported in biliary tract, as biliary intraepithelial neoplasm (BilIN), and in pancreas, as pancreatic intraepithelial neoplasm (PanIN). Both can evolve to invasive carcinomas, respectively cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC). Intraductal papillary neoplasms arise in biliary tract and pancreas. Intraductal papillary neoplasm of the biliary tract (IPNB) share common histologic and phenotypic features such as pancreatobiliary, gastric, intestinal and oncocytic types, and biological behavior with the pancreatic counterpart, the intraductal papillary mucinous neoplasm of the pancreas (IPMN). All these neoplastic lesions exhibit similar immunohistochemical phenotypes, suggesting a common carcinogenic process. Indeed, CCA and PDAC display similar clinic-pathological features as growth pattern, poor response to conventional chemotherapy and radiotherapy and, as a consequence, an unfavorable prognosis. The objective of this review is to discuss similarities and differences between the neoplastic lesions of the pancreas and biliary tract with potential implications on a common origin from similar stem/progenitor cells.

High-grade precursor lesions can be used as surrogate markers to identify the epicenter of periampullary carcinomas

Identifying the accurate origin of periampullary cancers is important because different origins may trigger different clinicopathological behaviors. The presence of intraepithelial precursor lesions, including high-grade pancreatic intraepithelial neoplasias (PanINs) and/or high-grade biliary intraepithelial neoplasias (BilINs), may be suggestive of the origin of the periampullary carcinoma in challenging cases. To prove the usefulness of high-grade intraepithelial precursor lesions in identifying the origin of ambiguous periampullary cancers, the status and grades of PanINs and BilINs were evaluated in 256 periampullary carcinomas with a well-defined cancer origin as a test set, including 114 pancreatic cancers, 82 distal bile duct cancers, 54 ampullary cancers, and 6 duodenal cancers. One hundred twelve periampullary carcinomas with clinically equivocal epicenter either by radiologic imaging or by endoscopic finding used as a validation set. High-grade PanINs were found more commonly in pancreatic cancers than in distal bile duct, ampullary, and duodenal cancers both in test (P = .002) and validation sets (P < .001). Similarly, high-grade BilINs were identified more frequently in distal bile duct cancers than in ampullary, pancreatic, and duodenal cancers both in test (P < .001) and validation sets (P = .039). High-grade PanINs were found most commonly in pancreatic cancers, whereas high-grade BilINs were seen most frequently in distal bile duct cancers. In addition, both high-grade PanINs and high-grade BilINs are uncommonly noted in ampullary or duodenal cancers. The recognition of high-grade intraepithelial lesions can help identify the primary origin of periampullary cancers, especially when the epicenter of the periampullary cancer is ambiguous.

Intraductal papillary neoplasm of the bile duct: a case report

Intraductal papillary neoplasm of the bile duct (IPNB) is a rare variant of bile duct tumors, characterized by papillary growth within the bile duct lumen and is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. IPNBs are mainly found in patients from Far Eastern areas, where hepatolithiasis and clonorchiasis are endemic. The Western experience, however, remains limited. In this article, we report a 56-year-old man, referred to our hospital because of deranged liver function tests. Further imaging modalities showed a cystic lesion of 9 cm diameter, arising from the left hepatic duct. Inlying was a heterogeneous, lobulated mass. The patient underwent a left hemihepatectomy and adjuvant chemotherapy. Despite recent advanced technologies, diagnosis of IPNB is still challenging, especially in western countries due to its rarity. Early identification and resection of lesions, even in asymptomatic or minimally symptomatic patients, are however important prognostic factors.

Histopathology of a benign bile duct lesion in the liver: Morphologic mimicker or precursor of intrahepatic cholangiocarcinoma

A bile duct lesion originating from intrahepatic bile ducts is generally regarded as an incidental pathologic finding in liver specimens. However, a recent study on the molecular classification of intrahepatic cholangiocarcinoma has focused on the heterogeneity of this carcinoma and has suggested that the cells of different origins present in the biliary tree may have a major role in the mechanism of oncogenesis. In this review, benign intrahepatic bile duct lesions—regarded in the past as reactive changes or remnant developmental anomalies and now noted to have potential for developing precursor lesions of intrahepatic cholangiocarcinoma—are discussed by focusing on the histopathologic features and its implications in clinical practice.

Biliary tumors with pancreatic counterparts

Some biliary diseases mimic pancreatic diseases pathologically as well as pathogenetically. Such diseases can be called "biliary diseases with pancreatic counterparts". Biliary intraepithelial neoplasm (BilIN), intraductal papillary neoplasm of bile ducts (IPNB), hepatobiliary mucinous cystic neoplasm (hMCN), and IgG4-inflammatory pseudotumor represent the biliary counterparts of pancreatic intraepithelial neoplasm (PanIN), intraductal papillary mucinous neoplasm of pancreas (IPMN), pancreatic MCN, and mass forming type 1 autoimmune pancreatitis (AIP), respectively. BilIN and PanIN represent pre-invasive intraepithelial stages of nodular sclerosing cholangiocarcinoma and pancreatic ductal adenocarcinoma, respectively. IPNB and IPMN are grossly visible, predominant papillary, intraductal neoplasms that may progress to invasive carcinoma. Morphologically similar MCNs with subepithelial ovarian-like stroma occur in both the hepatobiliary system as well as the pancreas. IgG4-inflammatory pseudotumor, usually of the lymphoplasmacytic type, and mass forming type 1 AIP represent IgG4-related disease in the biliary tree and pancreas respectively. The biliary tract, which is associated with the peribiliary glands, including the pancreatic acini, can be regarded as an incomplete pancreas, so several diseases mimicking pancreatic diseases may be expected to occur in the biliary tract (biliary diseases with pancreatic counterparts).

An S100P-positive biliary epithelial field is a preinvasive intraepithelial neoplasm in nodular-sclerosing cholangiocarcinoma

Nodular-sclerosing cholangiocarcinoma (NS-CCA) is a common CCA of the intrahepatic large, perihilar, and distal bile ducts. Intraepithelial biliary neoplasms, such as the mucosal extension of carcinoma and preinvasive neoplastic lesions (ie, biliary intraepithelial neoplasia) reportedly occur in the bile ducts around CCA. In the present study, we collectively refer to these intraepithelial lesions as "intraepithelial neoplasms of the bile duct (IENBs)". We examined the IENBs in 57 surgically resected cases of NS-CCA. S100P immunostaining was used to help detect IENBs. The IENBs formed field(s) of continuous neoplastic biliary epithelial cells and showed a flat, micropapillary, or papillotubular configuration. IENBs could be classified into 3 categories based on their atypia: group A (neoplastic but not enough for malignancy), B (neoplastic and sufficiently well differentiated for high-grade dysplasia), and C (overtly malignant and variably differentiated). IENB was found in 31 of 57 cases, with group C the most common (26 cases) followed by group B (22 cases) and group A (16 cases). The expression of cancer-related molecules and MIB-1 index of groups A and B differed from those of invasive CCA, whereas these features of group C were relatively similar to those of invasive CCA. In conclusion, IENB was not infrequently found in NS-CCA and could be classified into 3 grades. Preinvasive lesions (biliary intraepithelial neoplasias) are likely to be found in groups A and B, whereas cancerization would be included in group C. The classification of IENB may be useful for future studies of the preinvasive intraepithelial neoplastic lesions of NS-CCAs.

Systematic Review and Meta-analysis of Current Experience in Treating IPNB: Clinical and Pathological Correlates

OBJECTIVE

To systematically review studies reporting clinicopathological features of intraductal papillary neoplasm of the bile duct (IPNB) to provide evidence-based guidance for management.

BACKGROUND

IPNB is a rare tumor type. Management decisions are currently based upon anecdotal evidence and small case series. To data, there has been no systematic review of IPNB literature.

METHODS

MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched and data were extracted from relevant studies. Meta-analysis was used to pool study estimates. Evidence of association was determined by comparing pooled crude odds ratios (OR) derived from abstracted data.

RESULTS

Fifty-seven retrospective case series were included. At least 43% of 476 specimens contained invasive disease. Invasive tumors were found at significantly higher frequency in pancreaticobiliary than intestinal, gastric or oncocytic-type IPNB [pooled OR 2.5, 95% confidence interval (CI) 1.5-4.2, P < 0.001]. A significantly higher proportion of pancreaticobiliary tumors compared with intestinal tumors expressed MUC-1 [86.4% (95% CI 75.1%-94.7%) vs 13.2% (95% CI 4.6%-25.2%), respectively P < 0.001]. IPNB identified in centers from Asia were more likely to be intrahepatic and were less frequently invasive compared with those from Western centers. Pooled estimates of absolute survival after IPNB resection were 96% (95% CI 93%-99%) at 1 year, 79% (95% CI 69%-88%) at 3 years, and 65% (95% CI 46%-76%) at 5 years.

CONCLUSIONS

Early surgery is advisable for radiologically suspected IPNB as it is frequently invasive. The pathobiology of IPNB demonstrates geographic variation. Pancreaticobiliary IPNB expresses MUC1 and is more frequently associated with invasive disease than other IPNB subtypes.

Spread of Intraductal Papillary Neoplasm Arising from the Cystic Duct of the Biliary Tree

Intraductal papillary neoplasm of the bile duct (IPNB) is a variant type of the bile duct carcinoma characterized by intraductal growth. IPNB is also recognized as a precursor of invasive carcinoma. We describe herein an extremely rare case of IPNB arising from the cystic duct. A 68-year-old man was admitted to our hospital for investigation of epigastralgia and abnormal levels of biliary tract enzyme. Computed tomography and magnetic resonance imaging showed a mass lesion spreading from the cystic duct to the upper-middle bile duct. Endoscopic retrograde cholangiography demonstrated diffuse duct dilation with a grossly visible intraductal mass and amorphous blobs, suggesting the presence of mucobilia or scattered tumors. We performed extrahepatic bile duct resection with lymphadenectomy. Macroscopically, a friable papillary tumor originated from the cystic duct grows intraluminally into the bile duct. Pathologically, the tumor was found to be intramucosal adenocarcinoma spreading to the whole extrahepatic bile duct, which was compatible with IPNB. We should discuss the features and progression processes of IPNB through this precious case.

Molecular genetics and targeted therapeutics in biliary tract carcinoma

The primary malignancies of the biliary tract, cholangiocarcinoma and gallbladder cancer, often present at an advanced stage and are marginally sensitive to radiation and chemotherapy. Accumulating evidence indicates that molecularly targeted agents may provide new hope for improving treatment response in biliary tract carcinoma (BTC). In this article, we provide a critical review of the pathogenesis and genetic abnormalities of biliary tract neoplasms, in addition to discussing the current and emerging targeted therapeutics in BTC. Genetic studies of biliary tumors have identified the growth factors and receptors as well as their downstream signaling pathways that control the growth and survival of biliary epithelia. Target-specific monoclonal antibodies and small molecules inhibitors directed against the signaling pathways that drive BTC growth and invasion have been developed. Numerous clinical trials designed to test these agents as either monotherapy or in combination with conventional chemotherapy have been completed or are currently underway. Research focusing on understanding the molecular basis of biliary tumorigenesis will continue to identify for targeted therapy the key mutations that drive growth and invasion of biliary neoplasms. Additional strategies that have emerged for treating this malignant disease include targeting the epigenetic alterations of BTC and immunotherapy. By integrating targeted therapy with molecular profiles of biliary tumor, we hope to provide precision treatment for patients with malignant diseases of the biliary tract.

Characterization of intraductal papillary neoplasm of bile duct with respect to histopathologic similarities to pancreatic intraductal papillary mucinous neoplasm

Intraductal papillary neoplasm of bile duct (IPNB) is a papillary tumor covered by well-differentiated neoplastic epithelium with fine fibrovascular cores in the dilated bile ducts. It reportedly shows similarities to intraductal papillary mucinous neoplasm of pancreas (IPMN), to various degrees. Herein, IPNB was pathologically analyzed by classifying 52 cases into 4 groups based on the histopathologic similarities to IPMN: group A (identical to IPMN, 19 cases), group B (similar to but slightly different from IPMN, 18 cases), group C (vaguely similar to IPMN, 5 cases), and group D (different from IPMN, 10 cases). In group A, intrahepatic and perihilar regions were mainly affected, most cases were of low/intermediate or high grade without invasion, and gastric type was the most common phenotype, followed by oncocytic and intestinal types. In groups C and D, perihilar and distal bile ducts were affected, almost all cases were of high grade with invasion, and most of them were of intestinal and pancreatobiliary phenotypes. Most group B cases were of intestinal phenotype, and all were of high grade with or without invasion. In conclusion, these 4 groups of IPNB showed unique pathologic features and behaviors. Group A cases were less aggressive and shared many features with IPMN, whereas group C and D cases were more aggressive and mainly found in perihilar and distal bile ducts. Group B resembling IPMN was intermediate between them. This classification may be useful in clinical practice and holds promise for a novel approach to analyze IPNB tumorigenesis.

Clinical and biological significance of precursor lesions of intrahepatic cholangiocarcinoma

Cholangiocarcinoma (CC) is primarily a malignant tumor of older adults most prevalent in Southeast Asia, where liver fluke infestation is high. However the etiology in western countries is unknown. Although the incidence of extrahepatic cholangiocarcinoma has remained constant, incidence of intrahepatic CC (ICC) which differs in morphology, pathogenesis, risk factors, treatment and prognosis is increasing. While this increase is associated with hepatitis C virus infection, chronic nonalcoholic liver disease, obesity, and smoking, the pathogenesis of ICC and molecular alterations underlying the carcinogenesis are not completely elucidated. Benign biliary lesions such as biliary intraepithelial neoplasia, intraductal papillary neoplasm of the bile duct, von Meyenburg complex or bile duct hamartoma, and bile duct adenoma have been associated with ICC. For each of these entities, evidence suggests or supports a role as premalignant lesions. This article summarized the important biological significance of the precursor lesions of ICC and the molecular mechanisms that may be involved in intrahepatic cholangiocarcinogenesis.

Clinical practice guidelines for the management of biliary tract cancers 2015: the 2nd English edition

BACKGROUND

The Japanese Society of Hepato-Biliary-Pancreatic Surgery launched the clinical practice guidelines for the management of biliary tract and ampullary carcinomas in 2008. Novel treatment modalities and handling of clinical issues have been proposed after the publication. New approaches for editing clinical guidelines, such as the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system, also have been introduced for better and clearer grading of recommendations.

METHODS

Clinical questions (CQs) were proposed in seven topics. Recommendation, grade of recommendation and statement for each CQ were discussed and finalized by evidence-based approach. Recommendation was graded to grade 1 (strong) and 2 (weak) according to the concept of GRADE system.

RESULTS

The 29 CQs covered seven topics: (1) prophylactic treatment, (2) diagnosis, (3) biliary drainage, (4) surgical treatment, (5) chemotherapy, (6) radiation therapy, and (7) pathology. In 27 CQs, 19 recommendations were rated strong and 11 recommendations weak. Each CQ included the statement of how the recommendation was graded.

CONCLUSIONS

This guideline provides recommendation for important clinical aspects based on evidence. Future collaboration with cancer registry will be a key for assessment of the guidelines and establishment of new evidence. Free full-text articles and a mobile application of this guideline are available via http://www.jshbps.jp/en/guideline/biliary-tract2.html.

Tubulin β-III: a novel immunohistochemical marker for intrahepatic peripheral cholangiocarcinoma

AIMS

Our recent proteomic study identified tubulin β-III (TUBB3) as a potential tissue marker for intrahepatic cholangiocarcinomas (CCs). This validation study was conducted to see whether or not TUBB3 can serve as a novel immunohistochemical marker for peripheral CCs, using a large cohort (n = 197) covering various liver tumours and premalignant conditions.

METHODS AND RESULTS

Immunostaining using a monoclonal antibody demonstrated TUBB3 expression in 14/28 cases of peripheral CCs (50%), while its expression was significantly less common in perihilar CCs (6/40, 15%) (P = 0.002). No significant difference was identified in clinicopathological features between TUBB3-positive and -negative cases. TUBB3 expression was entirely negative in hepatocellular carcinomas, biliary premalignant lesions (i.e., biliary intraepithelial neoplasias, intraductal papillary neoplasms), peribiliary gland hamartomas (bile duct adenomas), and non-neoplastic biliary epithelium. TUBB3 expression was only focally noted in 2/12 cases of mixed hepatocellular and cholangiocarcinomas (<10% of cancer cells). Compared with other biliary (CK7 and CK19) and malignant markers (p53 and MUC1), TUBB3 was less sensitive but more specific for peripheral CCs. TUBB3 was also expressed in 40% of metastatic colorectal or breast cancers.

CONCLUSIONS

This study revealed that TUBB3 is a moderately sensitive and highly specific tissue marker for discriminating peripheral CCs from other primary liver tumours.

Cystic and micropapillary epithelial changes of peribiliary glands might represent a precursor lesion of biliary epithelial neoplasms

A tumorigenic role of peribiliary glands (PBGs) has been suggested recently. This study was performed to clarify the histological characteristics of PBGs showing cystic and micropapillary epithelial changes. From histological sections of a total of 938 autopsy livers, cases with cystic and micropapillary changes of the epithelial cells of intrahepatic PBGs were collected. PBGs with cystic change that lacked micropapillary epithelial changes were referred to as cystic lesion. Mucin staining and immunohistochemical analysis were performed, and the results were compared between cystic and micropapillary (C-P) lesions and cystic lesions. C-P and cystic lesions were observed in 9 (1 %) and 40 (4 %) , respectively. The atypia of micropapillary epithelium was usually mild, but in a single case, invasive adenocarcinoma accompanied a C-P lesion. Abundant mucin expression was observed in all cases of C-P lesion, which was similar to mucinous acini of normal PBGs rather than serous acini. Immunohistochemical analysis showed that MUC5AC was more frequently expressed in C-P lesions than in cystic lesions. Immunohistochemical expression of cyclin D1 and S100P was characteristically found in C-P lesions. Mean Ki-67 labeling index of C-P lesions was significantly higher than that of cystic lesions. The immunoprofile of C-P lesions was similar to that of the branch-type intraductal papillary mucinous neoplasm of the pancreas. These results suggest that C-P lesions may have neoplastic features and might represent a precursor of biliary epithelial neoplasms, including branch-type intraductal papillary neoplasm of the bile duct as well as mucin-producing cholangiocarcinoma, a concept that we have recently proposed.

Histological features of precancerous and early cancerous lesions of biliary tract carcinoma

Biliary tract carcinoma develops within the intrahepatic or extrahepatic biliary tree and gallbladder. Primary sclerosing cholangitis, hepatolithiasis, congenital choledochal cyst, liver fluke infection, pancreatobiliary maljunction, toxic exposures and hepatitis virus infection are risk factors for the development of human biliary carcinoma. The precise molecular abnormalities of biliary carcinogenesis are still unknown, but chronic inflammatory conditions induce the production of reactive oxygen or nitrogen species leading to DNA damage. Recent studies indicate that cholangiocarcinoma of the large bile duct may arise in premalignant lesions such as biliary intraepithelial neoplasm (BilIN) and intraductal papillary neoplasm of the bile duct (IPNB). BilIN and IPNB are generally confined to the large and septal-sized bile duct. BilINs are occasionally observed in non-biliary liver cirrhosis as well as chronic biliary disease. In contrast, the precursor lesion of intrahepatic cholangiocarcinoma of the small bile duct type remains unclear. We herein demonstrated the histological characteristics of different tumor development pathways from premalignant lesion to carcinoma in different sites of the biliary tree.

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.

Intraductal papillary neoplasms of the bile duct: stepwise progression to carcinoma involves common molecular pathways

Intraductal papillary neoplasms of the bile duct are still poorly characterized regarding (1) their molecular alterations during the development to invasive carcinomas, (2) their subtype stratification and (3) their biological behavior. We performed a multicenter study that analyzed these issues in a large European cohort. Intraductal papillary neoplasms of the bile duct from 45 patients were graded and subtyped using mucin markers and CDX2. In addition, tumors were analyzed for common oncogenic pathways, and the findings were correlated with subtype and grade. Data were compared with those from 22 extra- and intrahepatic cholangiocarcinomas. Intraductal papillary neoplasms showed a development from preinvasive low- to high-grade intraepithelial neoplasia to invasive carcinoma. Molecular and immunohistochemical analysis revealed mutated KRAS, overexpression of TP53 and loss of p16 in low-grade intraepithelial neoplasia, whereas loss of SMAD4 was found in late phases of tumor development. Alterations of HER2, EGFR, β-catenin and GNAS were rare events. Among the subtypes, pancreato-biliary (36%) and intestinal (29%) were the most common, followed by gastric (18%) and oncocytic (13%) subtypes. Patients with intraductal papillary neoplasm of the bile duct showed a slightly better overall survival than patients with cholangiocarcinoma (hazard ratio (cholangiocarcinoma versus intraductal papillary neoplasm of the bile duct): 1.40; 95% confidence interval: 0.46-4.30; P=0.552). The development of biliary intraductal papillary neoplasms of the bile duct follows an adenoma-carcinoma sequence that correlates with the stepwise activation of common oncogenic pathways. Further large trials are needed to investigate and verify the finding of a better prognosis of intraductal papillary neoplasms compared with conventional cholangiocarcinoma.

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.

Intraductal papillary neoplasms of the bile duct

Intraductal papillary neoplasm of the bile duct (IPNB) is a rare variant of bile duct tumors characterized by papillary growth within the bile duct lumen and is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm of the pancreas. IPNBs display a spectrum of premalignant lesion towards invasive cholangiocarcinoma. The most common radiologic findings for IPNB are bile duct dilatation and intraductal masses. The major treatment of IPNB is surgical resection. Ultrasonography, computed tomography, magnetic resonance image, and cholangiography are usually performed to assess tumor location and extension. Cholangioscopy can confirm the histology and assess the extent of the tumor including superficial spreading along the biliary epithelium. However, pathologic diagnosis by preoperative biopsy cannot always reflect the maximum degree of atypia, because IPNBs are often composed of varying degrees of cytoarchitectural atypia. IPNBs are microscopically classified into four epithelial subtypes, such as pancreatobiliary, intestinal, gastric, and oncocytic types. Most cases of IPNB are IPN with high-grade intraepithelial neoplasia or with an associated invasive carcinoma. The histologic types of invasive lesions are either tubular adenocarcinoma or mucinous carcinoma. Although several authors have investigated molecular genetic changes during the development and progression of IPNB, these are still poorly characterized and controversial.

Clinicopathological features and prognosis of mucin-producing bile duct tumor and mucinous cystic tumor of the liver: a multi-institutional study by the Japan Biliary Association

BACKGROUND

The aim of this study was to determine the clinicopathological features and surgical outcomes of mucinous cystic neoplasm of the liver (MCN) and mucin-producing intraductal papillary neoplasm of the intrahepatic bile duct (M-IPNB).

METHODS

We performed a multi-institutional, retrospective study of patients with MCN or M-IPNB pathologically defined by the presence or absence of an ovarian-like stroma.

RESULTS

The M-IPNB and MCN were diagnosed in 119 and nine patients, respectively. MCN was observed in female patients, while M-IPNB produced symptoms of cholangitis. M-IPNBs were classed as low or intermediate grade in 53 cases, high grade in 23 and invasive carcinoma in 43. Fifty-one of the M-IPNBs were the pancreatobiliary type (PT), 33 were the intestinal type (IT), 23 were the oncocytic type (OT), and 12 were the gastric type (GT). The 1-, 5- and 10-year survival rates for the 105 patients with M-IPNB were 96%, 84% and 81%, respectively, while the 5-year survival rate for patients with MCN was 100%. OT and GT M-IPNB had better 10-year survival rates than PT and IT M-IPNB.

CONCLUSIONS

Although MCN has different features from M-IPNB, both diseases have a good prognosis after resection. The cellular type of M-IPNB appears to predict outcome.

Clinicopathological significance of S100 protein expression in cholangiocarcinoma

BACKGROUND AND AIM

Cholangiocarcinoma arising in the large bile ducts undergoes a multistep carcinogenesis process in chronic biliary diseases, and biliary intraepithelial neoplasia is known as a precursor lesion. This study examined the expression of S100 proteins in the multistep cholangiocarcinogenesis to clarify their clinicopathological significance.

METHODS

Immunohistochemical analysis was performed for the expression of S100A2, S100A4, S100A6, and S100P. Bile concentrations of S100P were measured using enzyme-linked immunosorbent assay.

RESULTS

The immunohistochemical expression of the S100 proteins was increased in biliary intraepithelial neoplasia as well as invasive adenocarcinoma of perihilar cholangiocarcinoma. Among the proteins, S100P expression was most drastically increased during the multistep carcinogenesis process. In cases with perihilar and extrahepatic cholangiocarcinoma, the immunohistochemical expression of S100A2 in cholangiocarcinoma cells significantly correlated with the histological grade, lymph node metastasis, clinical stage, and a poor survival rate of the patients. The bile levels of S100P were increased significantly in patients with cholangiocarcinoma compared with those in patients with lithiasis. Receiver operating characteristic curve analysis showed that S100P bile concentration was an indicator of cholangiocarcinoma with a sensitivity of 93% and a specificity of 70%.

CONCLUSIONS

These results suggest that S100P may be useful for the detection of cholangiocarcinoma as tissue and bile biomarkers, and the immunohistochemical expression of S100A2 is a potential prognostic marker in cholangiocarcinoma patients.

Histological characteristics of biliary intraepithelial neoplasia-3 and intraepithelial spread of cholangiocarcinoma

The increasing grades of biliary intraepithelial neoplasia (BilIN) reflect multistep carcinogenesis of cholangiocarcinoma, BilIN-3 representing the carcinoma in situ stage. A different form of in situ growth form of cancer cells is the intraepithelial spreading of cholangiocarcinoma cells. We examined the histological characteristics of carcinoma in situ in the biliary tract on 64 partial hepatectomy specimens with a diagnosis of hepatolithiasis. We distinguished two forms of carcinoma in situ: BilIN-3 and intraepithelial spread of carcinoma (IES). BilIN-3 is defined by epithelial atypia gradually decreasing towards the transition to adjacent normal biliary epithelium. In IES, the lesion shows an abrupt transition to normal biliary epithelium, in which the intraepithelial carcinoma then tends to spread. BilIN-3 and IES were observed in 17 (94 %) and seven (39 %), respectively, in cases of invasive cholangiocarcinoma (n = 18), and neither of them was observed in cases without invasive cholangiocarcinoma (n = 46). Most lesions of BilIN-3 and IES microscopically showed a flat or pseudopapillary pattern. The less frequent micropapillary configuration was noted more often in BilIN-3. BilIN-3 was not observed in septal and small intrahepatic bile ducts, while IES was regularly observed in such bile ducts. Immunohistochemical analysis showed p53 to be expressed significantly more frequently in IES (29 %) than in BilIN-3 (8 %). In conclusion, carcinoma in situ in the biliary tract is morphologically heterogeneous, and it is important to distinguish BilIN-3 and intraepithelial carcinoma spreading as distinct lesions, to better understand their biology.

Oncogenic potential of cyclin kinase subunit-2 in cholangiocarcinoma

BACKGROUND

Cyclin kinase subunit-2 (Cks2), a member of the human Cks family, plays an important role in the regulation of meiosis and mitosis; and its abnormal expression is usually associated with carcinogenesis. However, its exact functions and molecular mechanisms remain unclear.

AIMS

To observe Cks2 expression in cholangiocarcinoma and explore its role in the carcinogenesis of cholangiocarcinoma and possible mechanism.

METHODS

Cks2 expression in cholangiocarcinoma was detected with immunostaining and RT-PCR. MTT, colony formation, immunofluorescence, flow cytometry and Western blotting were performed to explore the role of Cks2 in cholangiocarcinoma and possible mechanism.

RESULTS

Cks2 was significantly elevated in cholangiocarcinoma tissues and its over-expression was associated with poor differentiation, CA19-9 and poor prognosis. Furthermore, Cks2 down-regulation inhibited cholangiocarcinoma cell proliferation and colony formation in vitro, and the growth of cholangiocarcinoma xenografts in animals; especially, enhanced the sensitivity of cholangiocarcinoma cells to chemotherapy. We further found that Cks2 knockdown induced cholangiocarcinoma cell cycle arrest in G2/M phase through down-regulation of Cyclin A and Cyclin B1 and Bax up-regulation and activation, mitochondrial membrane permeabilization and caspase-3 activation, which resulted in facilitating cholangiocarcinoma apoptosis.

CONCLUSIONS

These findings suggest that Cks2 may serve as an independent prognostic factor in patients with cholangiocarcinoma, and play an important role in the carcinogenesis of cholangiocarcinoma by facilitating cell cycle progression and Bax-mediated mitochondrial caspase-dependent apoptosis.

Novel multimodality treatment sequencing for extrahepatic (mid and distal) cholangiocarcinoma

Neoadjuvant chemoradiation has demonstrated significant advantages in the management of pancreatic adenocarcinoma. A similar tumor in a nearby anatomical location is extrahepatic cholangiocarcinoma, which has proven to be largely unresponsive to current forms of therapy. Neoadjuvant therapy for hilar cholangiocarcinoma has been combined with surgical resection and/or liver transplantation with a 25-33 % complete pathological response rate. We propose a wider application of neoadjuvant chemoradiation for patients with distal cholangiocarcinoma and present our rationale for this form of treatment sequencing.

Hemobilia due to biliary intraepithelial neoplasia associated with Zollinger-Ellison syndrome

A 58-year-old man was transferred to us from his local hospital because of failure to control his gastrointestinal bleeding by endoscopic hemostasis. Abdominal imaging suggested a hypervascular tumor of the pancreatic head (36 mm diameter), and laboratory testing showed an elevated serum gastrin level (17,800 pg/mL). Gastroduodenal endoscopy revealed multiple duodenal ulcers and active bleeding from the ampulla of Vater. The selective arterial secretagogue injection test suggested a gastrinoma in the pancreatic head, but no gastrinoma in the pancreatic tail. The patient was diagnosed with solitary pancreatic head gastrinoma complicated by hemosuccus pancreaticus, and pancreaticoduodenectomy was performed. Intraoperatively, the diagnosis was changed to primary peripancreatic lymph node gastrinoma without pancreatic involvement. The gastrointestinal bleeding stopped postoperatively and serum gastrin levels returned to normal. Histological examination of the surgical specimens revealed a small submucosal gastrinoma in the duodenum (7 mm diameter). The final diagnosis was microgastrinoma of the duodenum with peripancreatic lymph node metastasis. The cause of bleeding from the ampulla of Vater was initially obscure, but eventually a hemorrhagic erosion with moderate atypia was found in the common bile duct, indicating biliary intraepithelial neoplasia (BilIN). This is the first report of hemobilia due to BilIN with gastrinoma.

Histological and immunohistological findings in biliary intraepithelial neoplasia arising from a background of chronic biliary disease compared with liver cirrhosis of non-biliary aetiology

AIMS

Hitherto, biliary intraepithelial neoplasia (BilIN) has been described in chronic biliary disease but rarely in non-biliary liver cirrhosis (LC). Intraepithelial neoplasia of the pancreas shows alterations in the expression of cell cycle and mucin core proteins. The aim of this study was to evaluate BilIN and reactive biliary lesions in biliary disease and non-biliary LC.

METHODS AND RESULTS

BilIN was found in 51% (33 of 65) of liver tissue cases of biliary disease, and in 11% (34 of 310) of the LC group. Immunohistologically, MUC5AC, an 'early phase' protein, and Ki67, reflecting 'late phase' expression, were identified with increasing degrees of dysplasia in both groups, but that expression was significantly higher in the biliary disease group. 'Early phase' cell cycle proteins, p16 (decrease) and p21 (increase) altered in both biliary and LC groups with increasing degrees of dysplasia.

CONCLUSIONS

We found BilIN in the large bile ducts of hepatitis B virus- and hepatitis C virus-related LC as well as in cases related to a biliary aetiology. The LC group was significantly less likely to show changes in the expression of MUC5AC and proliferative activity than the biliary group. Alterations in p16 and p21 reflected increasing degrees of dysplasia in both groups.

Effects of endoscopic sphincterotomy on biliary epithelium: A case-control study

AIM: To study the long-term effects of endoscopic sphincterotomy on biliary epithelium.

METHODS: This is a prospective case-control study. A total of 25 patients with a median age of 71 years (range 49-89 years) and prior endoscopic sphincterotomy (ES) for benign disease formed the first group. The median time from ES was 42 mo (range 8-144 mo). Another 25 patients with a median age of 76 years (range 44-94 mo) and similar characteristics who underwent current endoscopic retrograde cholangiopancreatography (ERCP) and ES for benign disease formed the second group (control group). Brush cytology of the biliary tree with p53 immunocytology was performed in all patients of both groups. ERCPs and recruitment were conducted at the Endoscopic Unit of Aretaieion University Hospital and Tzaneio Hospital, Athens, from October 2006 to June 2010.

RESULTS: No cases were positive or suspicious for malignancy. Epithelial atypia was higher in the first group (32% vs 8% in the second group, P = 0.034). Acute cholangitis and previous biliary operation rates were also higher in the first group (acute cholangitis, 60% vs 24% in the second group, P = 0.01; previous biliary operation, 76% vs 24% in the second group, P = 0.001). Subgroup analysis showed that previous ES was the main causal factor for atypia, which was not related to the time interval from the ES (P = 0.407). Two patients (8%) with atypia in the first group were p53-positive.

CONCLUSION: ES causes biliary epithelial atypia that represents mostly reactive/proliferative rather than premalignant changes. The role of p53 immunoreactivity in biliary atypia needs to be further studied.