Different expression patterns of mucin core proteins and cytokeratins during intrahepatic cholangiocarcinogenesis from biliary intraepithelial neoplasia and intraductal papillary neoplasm of the bile duct--an immunohistochemical study of 110 cases of hepatolithiasis

Cell lineage-specific immunohistochemical markers in biliary intraepithelial neoplasia: Implications for subclassification and grading

Biliary intraepithelial neoplasia (BilIN), a precursor to cholangiocarcinoma, is categorized into low- and high-grade based on histological characteristics. Although gastric, intestinal, and biliary phenotypes of BilIN have been identified, detailed analyses of their immunophenotypic profiles using cell lineage-specific markers remain limited. This study aimed to define the immunohistochemical profiles of BilIN lesions, subclassify them based on their immunophenotypes, and correlate these profiles with histological grades. We examined 77 BilIN lesions from extrahepatic bile ducts, including 30 low- and 47 high-grade lesions, using immunohistochemical staining for gastric (claudin-18, MUC5AC), intestinal (cadherin-17, glycoprotein A33), and biliary (carbohydrate sulfotransferase 4) markers, along with progression markers (S100P, IMP3). Expression levels were semiquantitatively scored and correlated with histopathological features. BilIN lesions were classified into four immunophenotypes: gastric (G-type), intestinal (I-type), gastrointestinal (GI-type), and biliary (B-type). Low-grade lesions comprised G- (33.3 %), GI- (40 %), I- (13.3 %), and B-types (13.3 %), while high-grade lesions included G- (40.4 %), GI- (29.8 %), I- (21.3 %), and B-types (8.5 %). In low-grade BilIN, G-type lesions corresponded to gastric mucous cells, I-type to intestinal epithelial cells, and B-type to bile duct epithelial cells, while most GI-type lesions exhibited mixed G- and I-type components. High-grade BilIN differentiation based solely on histological characteristics was challenging to delineate due to overlapping features among I-, GI-, and B-type cells. S100P and IMP3 expression levels were significantly elevated in high-grade lesions, particularly within the I+B-type BilIN group, with no notable differences in G- or GI-type BilIN. Immunophenotypic profiling with lineage-specific markers effectively subclassified BilIN, enhancing the understanding of its histogenesis and progression.

Morphomolecular Pathology and Genomic Insights into the Cells of Origin of Cholangiocarcinoma and Combined Hepatocellular-Cholangiocarcinoma

Cholangiocarcinomas are a highly heterogeneous group of malignancies that, despite recent progress in the understanding of their molecular pathogenesis and clinical management, continue to pose a major challenge to public health. The traditional view posits that cholangiocarcinomas derive from the neoplastic transformation of cholangiocytes lining the biliary tree. However, increasing genetic and experimental evidence has recently pointed to a more complex, and nuanced, scenario for the potential cell of origin of cholangiocarcinomas. Hepatocytes as well as hepatic stem/progenitor cells are being considered as additional potential sources, depending on microenvironmental contexts, including liver injury. The hypothesis of potentially diverse cells of origin for cholangiocarcinoma, albeit controversial, is certainly not surprising given the plasticity of the cells populating the liver as well as the existence of liver cancer subtypes with mixed histologic and molecular features. This review carefully examines the current pathologic, genomic, and experimental evidence supporting the existence of multiple cells of origin of liver and biliary tract cancers, with particular focus on cholangiocarcinoma and combined hepatocellular-cholangiocarcinoma.

A Case of Biliary Intraepithelial Neoplasm in a Young Man Diagnosed by Laparoscopic Hepatectomy to Treat Recurrent Intrahepatic Lithiasis and Cholangitis

INTRODUCTION

Biliary intraepithelial neoplasia (BilIN) is defined as a bile duct epithelial tumor with intraductal papillary neoplasia of the bile duct. BiIlN is a precancerous lesion of intrabiliary neoplasia. We performed laparoscopic hepatic resection for recurrent cholangitis due to intrahepatic lithiasis and diagnosed BilIN. This case suggests that it is necessary to consider the possibility of malignancy in cases of repeat cholangitis due to intrahepatic lithiasis.

CASE PRESENTATION

A 34-year-old man developed cholecystitis due to gallstones at the age of 25 years and underwent laparoscopic cholecystectomy at the age of 26 years. One year later, cholangitis developed, and 2 years later, acute pancreatitis developed due to bile duct stones. Three years later, at the age of 31 years, he underwent endoscopic lithotripsy for bile duct stones and cholangitis. At that time, intrahepatic lithiasis was also detected in segment 6, but there was no stricture in the bile duct, and he was kept under observation. Three years later, at the age of 34 years, cholangitis in the bile duct of segment 6 was observed, and endoscopic nasobiliary drainage was performed. At that time, no strictures or common bile duct stones were found in bile duct of segment 6; however, we decided to perform laparoscopic hepatic resection of the ventral region of segment 6 because of the recurrent cholangitis. Pathological examination revealed bile duct inflammation and BilIN-1 in the bile duct epithelium; the bile duct stump was negative.

CONCLUSIONS

We experienced a case of a young patient with recurrent cholangitis due to intrahepatic lithiasis and diagnosed BilIN after laparoscopic hepatectomy. In such a case, it is also necessary to select a strategy that considers the coexistence of precancerous lesions, such as BilIN.

Intraductal Papillary Neoplasms of the Bile Duct: Clinical Case Insights and Literature Review

BACKGROUND

Intraductal papillary neoplasms of the bile duct (IPNB) are rare precancerous lesions with implications for the development of cholangiocarcinoma (CCA). Recognizing IPNB and managing its recurrence pose challenges in clinical practice. We present two cases. Case 1: a 60-year-old man presented with an 8 × 8 × 9 cm hepatic cyst initially suspected to be a hydatid cyst. Histology post-resection revealed an IPNB with foci of adenocarcinoma. Despite negative oncologic margins, recurrence occurred eight years later as an rT2N0 lesion. Surgical resection was performed without adjuvant chemotherapy, resulting in the patient's survival at 48 months post-surgery. Case 2: a 28-year-old female with cognitive impairment was admitted with pulmonary embolism and a liver lesion diagnosed as a simple cyst. Subsequent evaluation revealed adenocarcinoma with local metastases, extensive vascular involvement, and thrombosis. Despite aggressive management, including thrombectomy and chemotherapy, the patient's condition deteriorated, leading to hepatic failure and eventual demise.

CONCLUSION

IPNB represents a rare premalignant subtype with a propensity for progression to CCA. R0 surgical resection typically offers favorable oncological outcomes with a minimal recurrence risk. Surgical intervention for localized resectable recurrence is both safe and feasible. International registries tracking IPNB recurrence are essential for advancing understanding and optimizing diagnosis, management, and treatment strategies.

A Review of Type 1 and Type 2 Intraductal Papillary Neoplasms of the Bile Duct

Intraductal papillary neoplasm of the bile duct (IPNB) is a heterogeneous disease similar to intraductal papillary mucinous neoplasm of the pancreas. These lesions have been recognized as one of the three major precancerous lesions in the biliary tract since 2010. In 2018, Japanese and Korean pathologists reached a consensus, classifying IPNBs into type l and type 2 IPNBs. IPNBs are more prevalent in male patients in East Asia and are closely related to diseases such as cholelithiasis and schistosomiasis. From a molecular genetic perspective, IPNBs exhibit early genetic variations, and different molecular pathways may be involved in the tumorigenesis of type 1 and type 2 IPNBs. The histological subtypes of IPNBs include gastric, intestinal, pancreaticobiliary, or oncocytic subtypes, but type 1 IPNBs typically exhibit more regular and well-organized histological features than type 2 IPNBs and are more commonly found in the intrahepatic bile ducts with abundant mucin. Due to the rarity of these lesions and the absence of specific clinical and laboratory features, imaging is crucial for the preoperative diagnosis of IPNB, with local bile duct dilation and growth along the bile ducts being the main imaging features. Surgical resection remains the optimal treatment for IPNBs, but negative bile duct margins and the removal of lymph nodes in the hepatic hilum significantly improve the postoperative survival rates for patients with IPNBs.

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.

Intrahepatic cholangiocarcinoma with extensive intraductal extension of high-grade biliary intraepithelial neoplasia: a case report

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) is frequently associated with precursor lesions, and biliary intraepithelial neoplasia (BilIN) may play a significant role in the development of ICC. However, the exact sequence and progression of these lesions remain to be elucidated. We report a rare case of ICC that exhibited extensive longitudinal intraductal extension of high-grade BilIN in the posterior bile ducts and involved the hepatic hilum and the peripheral hepatic parenchyma.

CASE PRESENTATION

A 70-year-old female presented with anorexia. Computed tomography (CT) revealed a 15 mm enhancing intrahepatic tumor extending to the right intrahepatic secondary confluence. This was associated with a 7 mm diameter cystic dilatation of the segment 6 bile duct (B6). Endoscopic retrograde cholangiopancreatography (ERCP) revealed stenosis at the bifurcation of the posterior bile duct branch. Bile cytology confirmed the diagnosis of adenocarcinoma cells. Therefore, the patient was diagnosed with an ICC involving the right glissonean pedicle and underwent a right hepatectomy and lymph node dissection. Histologic examination revealed the tumor consisted of moderately differentiated adenocarcinoma. In connection with this lesion, diffuse intraductal atypical epithelial cells, which were diagnosed as high-grade BilIN, was observed not only in the dilated B6 but in the entire posterior bile ducts, which measured approximately 120 mm in diameter. Furthermore, two distinct foci of adenocarcinomas were identified in the peripheral hepatic parenchyma. A lymph node metastasis was also present. The pathological diagnosis was ICC pT4N1M0 stage IVA. The patient underwent adjuvant chemotherapy and has shown no recurrence 5 years after surgery. Imaging modalities were unable to accurately assess the extent of the intraductal neoplastic lesions due to their low papillary or sessile intraductal tubular growth. No risk factors for BilIN development, which has the potential to predispose to cholangiocarcinoma, were identified in the present case.

CONCLUSIONS

We present a case of ICC involving the right hepatic hilum, accompanied by extensive longitudinal extensions of high-grade BilIN and multifocal microscopic invasions in peripheral hepatic parenchyma. Notably, the intraductal lesions involved the entire posterior intrahepatic bile ducts. The presence of biliary neoplasia with extensive intraductal extension, in conjunction with ICC, should be considered as a variant of BilIN.

Intraductal papillary neoplasm of the bile duct: review of updated clinicopathological and imaging characteristics

BACKGROUND

Intraductal papillary neoplasm of the bile duct (IPNB) is a relatively rare disease and is known as one of the premalignant lesions in the biliary tract. The concept of IPNB has changed through numerous studies and is still evolving. As a lesser studied clinical entity compared with its pancreatic counterpart, intraductal papillary mucinous neoplasm, IPNB has been described in many similar terms, including biliary papillomatosis, biliary intraductal papillary-mucinous neoplasm, and papillary cholangiocarcinoma. This is based on the diversity of histopathological spectrum of IPNB.

METHODS

This review investigated previous studies including original articles, case studies, and expert opinions. Recently, two types of IPNB (types 1 and 2) have been proposed and validated based on the content first established in the WHO 2010 criteria.

RESULTS

This review provides a comprehensive analysis of existing literature, summarizing the clinical, radiological, morphological, and pathological characteristics of IPNB.

CONCLUSION

Given the ongoing ambiguity and controversies surrounding IPNB, future research, including large population-based studies and molecular investigations, is essential to enhance understanding of this disease.

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.

Recent advances of three-dimensional bioprinting technology in hepato-pancreato-biliary cancer models

Hepato-pancreato-biliary (HPB) cancer is a serious category of cancer including tumors originating in the liver, pancreas, gallbladder and biliary ducts. It is limited by two-dimensional (2D) cell culture models for studying its complicated tumor microenvironment including diverse contents and dynamic nature. Recently developed three-dimensional (3D) bioprinting is a state-of-the-art technology for fabrication of biological constructs through layer-by-layer deposition of bioinks in a spatially defined manner, which is computer-aided and designed to generate viable 3D constructs. 3D bioprinting has the potential to more closely recapitulate the tumor microenvironment, dynamic and complex cell-cell and cell-matrix interactions compared to the current methods, which benefits from its precise definition of positioning of various cell types and perfusing network in a high-throughput manner. In this review, we introduce and compare multiple types of 3D bioprinting methodologies for HPB cancer and other digestive tumors. We discuss the progress and application of 3D bioprinting in HPB and gastrointestinal cancers, focusing on tumor model manufacturing. We also highlight the current challenges regarding clinical translation of 3D bioprinting and bioinks in the field of digestive tumor research. Finally, we suggest valuable perspectives for this advanced technology, including combination of 3D bioprinting with microfluidics and application of 3D bioprinting in the field of tumor immunology.

Intraductal tubulopapillary neoplasms of the bile ducts: identity, clinicopathologic characteristics, and differential diagnosis of a distinct entity among intraductal tumors

Among the mass-forming preinvasive (tumoral intraepithelial) neoplasms of the biliary tract, intraductal tubulopapillary neoplasms (ITPN-Bs) are increasingly being recognized as a separate category. By being intramucosal polypoid proliferations of dysplastic/neoplastic cells, they are highly similar to other members of the "intraductal neoplasms (IDNs)" category (namely, intraductal papillary neoplasms [IPNBs], and intraductal oncocytic papillary neoplasms [IOPNs]); however, they are distinguished by MUC6-expressing nonmucinous cells that lack intestinal differentiation and form striking tubular configuration. Their molecular/genetic profile is also proving to be different with frequent alterations in cell cycle and chromatin remodeling genes, which are quite uncommon in other IDNs and cholangiocarcinomas. Despite the conceptual overlaps, they are also very different from intracholecystic nonmucinous tubular neoplasms (ICTN) of the gallbladder with the latter being associated with Wnt/beta-catenin pathway alterations, and almost never invasive. In contrast, ITPN-Bs are invasive in an estimated 80% of the cases, although even invasive examples often exhibit a protracted course. Invasive carcinomas arising from ITPN-Bs are overall similar to cholangiocarcinomas (including small duct and large duct patterns) but also often have peculiar characteristics such as more nodular-compact (blunt invasion) pattern. Like other IDNs, the ITPN-Bs have also been classified in the past as intraductal-spreading type of cholangiocarcinomas (and they are still regarded as such in some publications). In small biopsies, they are prone to be mistaken as ordinary adenocarcinomas because of their tubular pattern and pancreatobiliary cytology although their relatively monotonous cytology and zones of back-to-back tubule formation can help in their correct identification. Clinical presentation of ITPN-Bs is generally similar to other intraductal neoplasms; however, in the intrahepatic component, they tend to be more nodular than cystic, and their snake-like intraductal growth pattern is often more striking. In the management (diagnosis and treatment) of these tumors that are in essence adenoma-carcinoma sequence, the invasive and noninvasive components ought to be evaluated separately. Minimally invasive examples are commonly curable, and even those more extensively invasive may have a surprisingly good prognosis. In summary, biliary ITPNs form a distinct category not only clinicopathologically, immunophenotypically, and molecular-wise but regarding their biological behavior as well.

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.

Development of intraductal papillary neoplasm of the bile duct in patients with occupational cholangiocarcinoma

This study aimed to investigate the clinicopathological findings of intraductal papillary neoplasm of the bile duct (IPNB) in patients with occupational cholangiocarcinoma caused by exposure to 1,2-dichloropropane and/or dichloromethane to elucidate the development of IPNB to cholangiocarcinoma. The clinicopathological findings of 17 IPNB lesions according to the size (1.5-20 mm in diameter) and their comparison between type 1 (n = 9) and type 2 IPNBs (n = 8) were investigated. An IPNB of <5 mm in size was classified as micro IPNB (n = 7), while those ≥5 mm in size were classified as ordinary IPNB (n = 10). Both types 1 and 2 IPNBs were observed in micro IPNB, and their proportions were not different between micro and ordinary IPNBs. The clinicopathological characteristics of types 1 and 2 IPNBs were fundamentally similar to those previously reported. IPNB with invasive carcinoma was only found in ordinary IPNB although the proportions of low-grade and high-grade epithelium were not different between micro IPNB and ordinary IPNB. All IPNB exhibited γH2AX and S100P, indicating the occurrence of DNA injury and malignant transformation in micro and ordinary IPNBs. These results indicate that the carcinogens may induce micro IPNB with types 1 or 2 at the initiation and then develop ordinary IPNB with types 1 or 2, subsequently, progressing to IPNB with invasive carcinoma in patients with occupational cholangiocarcinoma.

Understanding the Clinical Significance of MUC5AC in Biliary Tract Cancers

Biliary tract cancers (BTC) arise from biliary epithelium and include cholangiocarcinomas or CCA (including intrahepatic (ICC) and extrahepatic (ECC)) and gallbladder cancers (GBC). They often have poor outcomes owing to limited treatment options, advanced presentations, frequent recurrence, and poor response to available systemic therapy. Mucin 5AC (MUC5AC) is rarely expressed in normal biliary epithelium, but can be upregulated in tissues of benign biliary disease, premalignant conditions (e.g., biliary intraepithelial neoplasia), and BTCs. This mucin's numerous glycoforms can be divided into less-glycosylated immature and heavily-glycosylated mature forms. Reported MUC5AC tissue expression in BTC varies widely, with some associations based on cancer location (e.g., perihilar vs. peripheral ICC). Study methods were variable regarding cancer subtypes, expression positivity thresholds, and MUC5AC glycoforms. MUC5AC can be detected in serum of BTC patients at high concentrations. The hesitancy in developing MUC5AC into a clinically useful biomarker in BTC management is due to variable evidence on the diagnostic and prognostic value. Concrete conclusions on tissue MUC5AC are difficult, but serum detection might be relevant for diagnosis and is associated with poor prognosis. Future studies are needed to further the understanding of the potential clinical value of MUC5AC in BTC, especially regarding predictive and therapeutic value.

Preneoplastic lesions in the liver: Molecular insights and relevance for clinical practice

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) are the most frequent primary liver cancers, accounting for approximately 80% and 15%, respectively. HCC carcinogenesis occurs mostly in cirrhosis and is a complex multi-step process, from precancerous lesions (low-grade and high-grade dysplastic nodules) to progressed HCC. During the different stages of liver carcinogenesis, there is an accumulation of pathological, genetic and epigenetic changes leading to initiation, malignant transformation and finally tumour progression. In contrast, a small subset of HCC occurs in normal liver from the transformation of hepatocellular adenoma (HCA), a benign hepatocellular tumour. The recent molecular classification enables to stratify HCAs according to their risk of complication, in particular malignant transformation, associated with mutations in exon 3 of the catenin beta 1 (CTNNB1) gene. Cholangiocarcinoma (CCA) derives from the multistep malignant transformation of preneoplastic lesions, like biliary intraepithelial neoplasia (BilIN) and intraductal papillary neoplasm of the bile duct (IPNB), for which a pre-operative diagnosis remains difficult. Different genetic alterations are involved in BilIN and IPNB progression, leading to the development of tubular or intestinal adenocarcinoma. The aims of this review are to describe the main clinical and molecular features of preneoplastic lesions leading to the development of HCC and CCA, their implications in clinical practice and the perspectives for future research.

Integrative analysis reveals early and distinct genetic and epigenetic changes in intraductal papillary and tubulopapillary cholangiocarcinogenesis

OBJECTIVE

A detailed understanding of the molecular alterations in different forms of cholangiocarcinogenesis is crucial for a better understanding of cholangiocarcinoma (CCA) and may pave the way to early diagnosis and better treatment options.

DESIGN

We analysed a clinicopathologically well-characterised patient cohort (n=54) with high-grade intraductal papillary (IPNB) or tubulopapillary (ITPN) neoplastic precursor lesions of the biliary tract and correlated the results with an independent non-IPNB/ITPN associated CCA cohort (n=294). The triplet sample set of non-neoplastic biliary epithelium, precursor and invasive CCA was analysed by next generation sequencing, DNA copy number and genome-wide methylation profiling.

RESULTS

Patients with invasive CCA arising from IPNB/ITPN had better prognosis than patients with CCA not associated with IPNB/ITPN. ITPN was localised mostly intrahepatic, whereas IPNB was mostly of extrahepatic origin. IPNB/ITPN were equally associated with small-duct and large-duct type intrahepatic CCA. IPNB exhibited mutational profiles of extrahepatic CCA, while ITPN had significantly fewer mutations. Most mutations were shared between precursor lesions and corresponding invasive CCA but ROBO2 mutations occurred exclusively in invasive CCA and CTNNB1 mutations were mainly present in precursor lesions. In addition, IPNB and ITPN differed in their DNA methylation profiles and analyses of latent methylation components suggested that IPNB and ITPN may have different cells-of-origin.

CONCLUSION

Integrative analysis revealed that IPNB and ITPN harbour distinct early genetic alterations, IPNB are enriched in mutations typical for extrahepatic CCA, whereas ITPN exhibited few genetic alterations and showed distinct epigenetic profiles. In conclusion, IPNB/ITPN may represent a distinctive, intermediate form of intrahepatic and extrahepatic cholangiocarcinogenesis.

Gastrointestinal and Pancratohepatobiliary Cancers: A Comprehensive Review on Epidemiology and Risk Factors Worldwide

A significant number of cancer cases are afflicted by gastrointestinal cancers annually. Lifestyle and nutrition have a huge effect on gastrointestinal function, and unhealthy habits have become quite widespread in recent decades, culminating in the rapid growth of gastrointestinal cancers. The most prevalent cancers are lip and mouth cancer, esophageal cancer, gastric cancer, liver and bile duct cancer, pancreatic cancer, and colorectal cancer. Risk factors such as red meat consumption, alcohol consumption, tea, rice, viruses such as Helicobacter pylori and Ebstein Bar Virus (EBV), along with reduced physical activity, predispose the gastrointestinal tract to damage and cause cancer. According to the rapid increase of cancer incidence and late diagnosis of gastrointestinal malignancies, further epidemiological researches remain necessary in order to make appropriate population-based preventive policies. In this study, we reviewed clinical symptoms, risk factors, preventative measures, as well as incidence and mortality rates of gastrointestinal malignancies worldwide with focus on Iranian population.

Intracholecystic papillary neoplasm of the gallbladder diagnosed during follow-up of Menetrier's disease: A case report

Intracholecystic papillary neoplasm of the gallbladder (ICPN) is a type of intraductal papillary neoplasm of the bile duct that occurs in the gallbladder, and is a relatively newer concept. Therefore, there are few reports regarding ICPN. Menetrier's disease is a rare disease characterized by giant hypertrophy of the gastric folds that causes protein-losing gastroenteropathy (PLG). Although Menetrier's disease is a known risk factor for gastric adenocarcinoma, the association between Menetrier's disease and malignancy other than a malignancy of the stomach is unclear. A 69-year-old man presented to the Hokkaido Social Work Association Obihiro Hospital with gallbladder tumours diagnosed by ultrasonography at a previous institution. In addition, he had previously been diagnosed with PLG due to Menetrier's disease. Abdominal contrast-enhanced computed tomography (CT) revealed an irregular mass with a contrast effect at the fundus of the gallbladder on the free abdominal cavity side. Positron emission tomography-CT showed a tumour with a standard uptake value (SUV) of 8.28 at the fundus of the gallbladder. Cholecystectomy and resection of the gallbladder bed were performed. Based on the microscopy findings, the patient was diagnosed with ICPN. Although he had postoperative ileus, he was discharged 14 days postoperatively due to improvement through conservative treatment. Such cases of ICPN complicated with Menetrier's disease are extremely rare. However, patients with Menetrier's disease may need to be screened for malignancies.

A clinicopathological reappraisal of intraductal papillary neoplasm of the bile duct (IPNB): a continuous spectrum with papillary cholangiocarcinoma in 181 curatively resected cases

BACKGROUND

Intraductal papillary neoplasm of the bile-duct (IPNB) has recently been further subclassified into "so-called IPNBs" (Type-1) and "narrow-sense papillary cholangiocarcinomas" (Type-2), but their differential diagnosis is challenging. This study aimed to reevaluate Type-1 and Type-2 IPNBs.

METHODS

Consecutive patients who underwent papillary bile-duct tumor resection were included. Using six pathological features (location, mucin secretion, histological architecture, histological type, presence of a low/intermediate-dysplasia component, and proportion of the invasive component), all papillary tumors were scored. Tumors scoring 5-6 were classified as Type-1, 0-1 as Type-2, and 2-4 as Type-Unclassifiable.

RESULTS

The 181 papillary bile-duct tumor patients were divided into three groups, consisting of 12 Type-1, 46 Type-2, and 123 Type-Unclassifiable-gray-zone lesions between Type-1 and Type-2 that constituted the largest proportion of papillary tumors. Type-1 tumors were pathologically the least advanced, while the other types showed gradual advancement. The 5-year survival rate was better for patients with Type-1 tumors than for those with Type-Unclassifiable or Type-2 tumors.

CONCLUSION

The scoring system worked well to delineate a continuous spectrum of pathologic features ranging from Type-1, through Type-Unclassifiable, to Type-2, the latter two being challenging to differentially diagnose. Type-1 is regarded as an early neoplasm of Type-Unclassifiable and Type-2.

An immunohistochemical panel of insulin-like growth factor II mRNA-binding protein 3 (IMP3), enhancer of zeste homolog 2 (EZH2), and p53 is useful for a diagnosis in bile duct biopsy

Bile duct biopsy is being increasingly performed in number for a definite diagnosis of cholangiocarcinoma. However, difficulties are associated with a histopathological diagnosis because of the limited small amount of specimen obtained and crash artifact. The aim of the present study was to identify useful diagnostic immunohistochemical markers in bile duct biopsy that support a histological diagnosis. Fifty-one bile duct biopsy samples, including 26 samples taken from patients with cholangiocarcinoma, 11 with intraductal papillary neoplasm of the bile duct (IPNB), and 14 with benign bile duct lesions, were examined. Histology and the immunohistochemical expression of insulin-like growth factor II mRNA-binding protein 3 (IMP3), enhancer of zeste homolog 2 (EZH2), and p53 were assessed. They were then evaluated for their usefulness as diagnostic markers of malignancy. The diagnostic sensitivity and accuracy of the institutional histological diagnosis were 53.8% and 70.0%, respectively. The diagnostic sensitivity and accuracy of IMP3, EZH2, and p53 were 69.2% and 80.0%, 76.9% and 85.0%, and 50.0% and 67.5%, respectively. Immunohistochemical staining for EZH2; the combination of either 2 of IMP3, EZH2, and p53; or the combination of IMP3, EZH2, and p53 significantly increased sensitivity and accuracy over those of the institutional histological diagnosis (p<0.05). In conclusion, an immunohistochemical panel consisting of IMP3, EZH2, and p53 increases the diagnostic sensitivity and accuracy of bile duct biopsy for the diagnosis of cholangiocarcinoma.

Dysplasia and carcinoma of the gallbladder: pathological evaluation, sampling, differential diagnosis and clinical implications

Pathological evaluation of gallbladder neoplasia remains a challenge. A significant proportion of cases presents as clinically and grossly inapparent lesions, and grossing protocols are not well established. Among epithelial alterations, pseudo-pyloric gland metaplasia is ubiquitous and of no apparent consequence, whereas goblet cell metaplasia and a foveolar change in surface cells require closer attention. Low-grade dysplasia is difficult to objectively define and appears to be clinically inconsequential by itself; however, extra sampling is required to exclude the possibility of accompanying more significant lesions. For high-grade dysplasia ('high-grade BilIN', also known as 'carcinoma in situ'), a complete sampling is necessary to rule out invasion. Designating in-situ or minimally invasive carcinomas limited to muscularis or above as early gallbladder carcinoma (EGBC) helps to alleviate the major geographical differences (West/East) in the criteria for 'invasiveness' to assign a case to pTis or pT1. Total sampling is crucial in proper diagnosis of such cases. A subset of invasive GBCs (5-10%) arise from the intracholecystic neoplasm (ICN, 'adenoma-carcinoma sequence') category. Approximately two-thirds of ICNs have invasive carcinoma. However, this propensity differs by subtype. True 'pyloric gland adenomas' (> 1 cm) are uncommon and scarcely associated with invasive carcinoma. A distinct subtype of ICN composed of tubular, non-mucinous MUC6⁺ glands [intracholecystic tubular non-mucinous neoplasm (ICTN)] forms a localised pedunculated polyp. Although it is morphologically complex and high-grade, it appears to be invasion-resistant. Some of the invasive carcinoma types in the gallbladder have been better characterised recently with adenosquamous, neuroendocrine, poorly cohesive and mucinous carcinomas often being more advanced and aggressive.

A case report of mucinous adenocarcinoma derived from intra-ampullary papillary-tubular neoplasm with a malignant course

Background

Intra-ampullary papillary-tubular neoplasm (IAPN) has been classified as a Vater papillary tumor. The prognosis of IAPN is generally relatively good. Here, we describe a patient with a mucinous adenocarcinoma cluster in the Vater papilla of IAPN origin.

Clinical presentation

The patient was a 66-year-old man who was admitted to our hospital after a diagnosis of pancreatic head carcinoma based on a pancreatic duct dilatation found on abdominal ultrasound. CT showed a 40 mm lesion in the pancreatic head and expansion of the main pancreatic duct to a maximum diameter of 9 mm on the caudal side of the lesion. The extrahepatic bile duct had also expanded to a maximum diameter of 8 mm. PET/CT showed fluorodeoxyglucose (FDG) accumulation of SUV_max 6.02 that corresponded to the tumor in the pancreatic head, though it did not suggest distant metastasis. The patient was diagnosed with pancreatic head carcinoma T3 N0 M0 Stage IIA and underwent a pancreaticoduodenectomy. Pathology indicated that the tumor in the pancreatic head was a benign inflammatory lesion. On the other hand, the papillotubular tumor pervading the lumen in the duodenal papillary common channel met the criteria for IAPN, and a mucinous adenocarcinoma cluster found in the surrounding stroma suggested malignant transformation of IAPN. No metastasis to lymph nodes was demonstrated. With regard to the mucus phenotype of each lesion, the IAPN was MUC2 and MUC5AC positive, while the mucinous adenocarcinoma was MUC2-positive and MUC5AC-negative. In addition, CD10 was negative in both lesions, suggesting that mucus transformation from the gastric type to the intestinal type was a key element. A blood test 10 months after surgery showed increased CA19-9 (105 U/mL) and CEA (7.1 ng/mL). Abdominal CT showed multiple cystoid nodes in the liver, which were diagnosed as multiple liver metastases of mucinous adenocarcinoma transformed from the IAPN.

Conclusions

We reported a case with IAPN that developed in the Vater papilla, which took an extremely malignant course. IAPN generally has a good prognosis, but it is important to understand that a malignant course may occur.

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.

Decreased alpha-1,4-linked N-acetylglucosamine glycosylation in biliary tract cancer progression from biliary intraepithelial neoplasia to invasive adenocarcinoma

Biliary tract cancer (BTC) is typically lethal due to the difficulty of early stage diagnosis. Thus, novel biomarkers of BTC precursors are necessary. Biliary intraepithelial neoplasia (BilIN) is a major precursor of BTC and is classified as low or high grade based on cell atypia. In normal gastric mucosa, gastric gland mucin‐specific O‐glycans are unique in having α1,4‐linked N‐acetylglucosamine (αGlcNAc) attached to MUC6. Previously, we reported that αGlcNAc functions as a tumor suppressor of differentiated‐type gastric adenocarcinoma and that decreased αGlcNAc glycosylation on MUC6 in gastric, pancreatic, and uterine cervical neoplasms occurs in cancer as well as in their precursor lesions. However, αGlcNAc and MUC6 expression patterns in biliary tract neoplasms have remained unclear. Here, we analyzed MUC5AC, MUC6, and αGlcNAc expression status in 51 BTC cases and compared the expression of each with progression from low‐grade BilIN to invasive adenocarcinoma (IAC). The frequency of αGlcNAc‐positive and MUC6‐positive lesions decreased with tumor progression. When we compared each marker’s expression level with tumor progression, we found that the MUC6 expression score in IAC was significantly lower than in low‐grade or high‐grade BilIN (P < 0.001 or P < 0.01, respectively). However, the αGlcNAc expression score was low irrespective of histological grade, and also lower than that of MUC6 across all histological grades (P < 0.001 for low‐grade and high‐grade BilIN, and P < 0.01 for IAC). These results suggest that decreased expression of αGlcNAc relative to MUC6 marks the initiation of BTC progression.

Clinicopathological characteristics of intraductal papillary neoplasm of the bile duct: a Japan-Korea collaborative study

BACKGROUND

The prevalent location and incidence of intraductal papillary neoplasm of the bile duct (IPNB) and invasive carcinoma associated with them have varied markedly among studies due to differences in diagnostic criteria and tumor location.

METHODS

IPNBs were classified into two types: Type 1 IPNB, being histologically similar to intraductal papillary mucinous neoplasm of the pancreas, and Type 2 IPNB, having a more complex histological architecture with irregular papillary branching or foci of solid-tubular components. Medical data were evaluated.

RESULTS

Among 694 IPNB patients, 520 and 174 had Type 1 and Type 2, respectively. The levels of AST, ALT, ALP, T. Bil, and CEA were significantly higher in patients with Type 2 than in those with Type 1. Type 1 IPNB was more frequently located in the intrahepatic bile duct than Type 2, whereas Type 2 was more frequently located in the distal bile duct than Type 1 IPNB (P < 0.001). There were significant differences in 5-year cumulative survival rates (75.2% vs 50.9%; P < 0.0001) and 5-year cumulative disease-free survival rates (64.1% vs 35.3%; P < 0.0001) between the two groups.

CONCLUSION

Type 1 and Type 2 IPNBs differ in their clinicopathological features and prognosis. This classification may help to further understand IPNB.

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.

Mucins in pancreatic cancer: A well-established but promising family for diagnosis, prognosis and therapy

Mucins are a family of multifunctional glycoproteins that mostly line the surface of epithelial cells in the gastrointestinal tract and exert pivotal roles in gut lubrication and protection. Pancreatic cancer is a lethal disease with poor early diagnosis, limited therapeutic effects, and high numbers of cancer‐related deaths. In this review, we introduce the expression profiles of mucins in the normal pancreas, pancreatic precursor neoplasia and pancreatic cancer. Mucins in the pancreas contribute to biological processes such as the protection, lubrication and moisturization of epithelial tissues. They also participate in the carcinogenesis of pancreatic cancer and are used as diagnostic biomarkers and therapeutic targets. Herein, we discuss the important roles of mucins that lead to the lethality of pancreatic adenocarcinoma, particularly MUC1, MUC4, MUC5AC and MUC16 in disease progression, and present a comprehensive analysis of the clinical application of mucins and their promising roles in cancer treatment to gain a better understanding of the role of mucins in pancreatic cancer.

Prognostic Factors for Surgically Resected Intraductal Papillary Neoplasm of the Bile Duct: A Retrospective Cohort Study

BACKGROUND

To date, postoperative prognostic factors for intraductal papillary neoplasm of the bile duct (IPNB) have not been well-established. This study aimed to examine the histopathologic features and postoperative prognosis of the two IPNB subclassifications, as well as factors affecting prognosis, based on the authors' experience at a single institution.

METHODS

The study enrolled 83 patients who underwent surgical resection for pathologically diagnosed IPNB at the authors' institution. The clinicopathologic features and postoperative outcomes for these patients were examined. The study also investigated postoperative prognostic factors for IPNB using uni- and multivariate analyses.

RESULTS

More than half of the tumors (64%) diagnosed as IPNB were early-stage cancer (UICC Tis or T1). However, none were diagnosed as benign. The multivariate analysis showed that lymph node metastasis (hazard ratio [HR], 5.78; p = 0.002) and bile duct margin status with carcinoma in situ (D-CIS; HR, 5.10; p = 0.002) were independent prognostic factors, whereas MUC6 expression showed only a marginal influence on prediction of prognosis (HR, 0.32; p = 0.07). The tumor recurrence rate and the proportion of locoregional recurrence were significantly greater among the patients with D-CIS than among those with negative bile duct margins, including those patients with low-grade dysplasia. The patients with D-CIS showed a significantly poorer prognosis than those with negative bile duct margins (5-year survival, 38% versus 87%; p = 0.0002).

CONCLUSIONS

Evaluation of resected IPNBs showed cancer in all cases. Avoiding positive biliary stumps during surgery, including resection of carcinoma in situ, would improve the prognosis for patients with IPNB.

Biliary intraductal tubule-forming neoplasm: a whole exome sequencing study of MUC5AC-positive and -negative cases

AIMS

Biliary intraductal tubular neoplasms that are non-mucinous and negative for mucin 5AC (MUC5AC) are called intraductal tubulopapillary neoplasms (ITPNs). Intraductal tubular neoplasms with mucinous cytoplasm and MUC5AC positivity also occur and their nature remains unclear, although some pathologists may classify these as 'intraductal papillary neoplasms of the bile duct (IPNBs) of gastric type'. This study aimed to elucidate genetic features of biliary intraductal tubular neoplasms.

METHODS AND RESULTS

Six resected cases of biliary intraductal neoplasm with >70% tubular configuration were characterised by clinicopathological examination and whole exome sequencing, and the findings obtained were compared between MUC5AC-negative (n = 2) and -positive cases (n = 4). The intraductal tumours consisted of the pancreatobiliary-type epithelium with high-grade dysplasia arranged in back-to-back tubules. Both of the two MUC5AC-negative cases were non-invasive neoplasms and developed in the liver, whereas all MUC5AC-positive cases had invasive carcinoma and were present in the intrahepatic (n = 2), perihilar (n = 1) and distal bile ducts (n = 1). In an exome-sequencing study, MUC5AC-negative cases harboured mutations in CTNNB1, SF3B1, BAP1 and BRCA1 (one case each). KRAS mutations were observed in three of four MUC5AC-positive cases (75%) but none of the MUC5AC-negative neoplasms. Compared to published data, known driver genes of other intraductal neoplasms of the pancreatobiliary system (e.g. APC, CTNNB1, STK11, GNAS and PIK3CA) were wild-type in all but one MUC5AC-negative case with CTNNB1 mutation. Chromatin modifiers (ARID1A, BAP1 and KMT2C) were also altered in MUC5AC-positive cases, similar to usual cholangiocarcinomas.

CONCLUSIONS

This exome-sequencing study suggested that MUC5AC-negative biliary ITPNs are genetically distinct from pancreatic ITPNs and IPNBs. They may also biologically differ from MUC5AC-positive tubular neoplasms despite morphological resemblance.

Characterization of Intraductal Papillary Neoplasm of the Bile Duct with Respect to the Histopathologic Similarities to Pancreatic Intraductal Papillary Mucinous Neoplasm

Intraductal papillary neoplasms of the bile duct (IPNBs) are known to show various pathologic features and biological behaviors. Recently, two categories of IPNBs have been proposed based on their histologic similarities to pancreatic intraductal papillary mucinous neoplasms (IPMNs): type 1 IPNBs, which share many features with IPMNs; and type 2 IPNBs, which are variably different from IPMNs. The four IPNB subtypes were re-evaluated with respect to these two categories. Intestinal IPNBs showing a predominantly villous growth may correspond to type 1, while those showing papillay-tubular or papillay-villous growth correspond to type 2. Regarding gastric IPNB, those with regular foveolar structures with varying numbers of pyloric glands may correspond to type 1, while those with papillary-foveolar structures with gastric immunophenotypes and complicated structures may correspond to type 2. Pancreatobiliary IPNBs that show fine ramifying branching may be categorized as type 1, while others containing many complicated structures may be categorized as type 2. Oncocytic type, which displays solid growth or irregular papillary structures, may correspond to type 2, while papillary configurations with pseudostratified oncocytic lining cells correspond to type 1. Generally, type 1 IPNBs of any subtype develop in the intrahepatic bile ducts, while type 2 IPNBs develop in the extrahepatic bile duct. These findings suggest that IPNBs arising in the intrahepatic ducts are biliary counterparts of IPMNs, while those arising in the extrahepatic ducts display differences from prototypical IPMNs. The recognition of these two categories of IPNBs with reference to IPMNs and their anatomical location along the biliary tree may deepen our understanding of IPNBs.

Peribiliary glands: development, dysfunction, related conditions and imaging findings

Peribiliary glands are minute structures that are distributed along the intrahepatic large bile ducts, extrahepatic bile duct, and cystic duct. These glands regulate many physiological functions, such as enzyme secretion. Pancreatic exocrine tissues and enzymes are often observed in peribiliary glands; thus, peribiliary glands are involved in enzyme secretion. As such, these glands can be affected by conditions such as IgG4-related sclerosing cholangitis based on commonalities with their pancreatic counterparts. Cystic changes in peribiliary glands can occur de novo, as part of a congenital syndrome, or secondary to insults such as alcoholic cirrhosis. Biliary tree stem/progenitor cells have recently been identified in peribiliary glands. These cells are involved in turnover and regeneration of biliary epithelia as well as in sclerosing reactions in some pathological conditions, such as primary sclerosing cholangitis and hepatolithiasis. Notably, hepatolithiasis is involved in mucin secretion by the peribiliary glands. Additionally, these cells are associated with the manifestation of several neoplasms, including intraductal papillary neoplasm, cystic micropapillary neoplasm, and cholangiocarcinoma. Normal peribiliary glands themselves are particularly small structures that cannot be recognized using any available imaging modalities; however, these glands are closely associated with several diseases, as mentioned above, which have typical imaging features. Therefore, knowledge of the basic pathophysiology of peribiliary glands is helpful for understanding biliary diseases associated with the peribiliary glands.

Cystic intraductal papillary neoplasms with infiltrating carcinoma of the intrahepatic bile duct: A case report

INTRODUCTION

Intraductal papillary neoplasms of the bile duct (IPNB) is a kind of rare disorder with low incidence but high misdiagnosis due to untypical symptoms and non-specific laboratory indicators. Herein, we report a case of cystic type IPNB with infiltrating carcinoma of the intrahepatic bile duct presented as a single giant cystic mass of the liver.

PATIENT CONCERNS

A 51-year-old woman was admitted due to right upper abdominal discomfort for 10 months. Physical examination indicated no specific finding. Laboratory tests showed that serum total bilirubin and carcinoembryonic antigen level was mildly elevated. Ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI) of abdomen indicated a giant lobulated cystic lesion involving the left, right and the caudate lobes of liver. There were multiple small nodules of different sizes with papillary or coral reef-like pattern protruding into the cystic lumen from the inner wall.

DIAGNOSIS

The patient was diagnosed as malignant tumors of intrahepatic bile duct.

INTERVENTIONS

She received radical resection of the lesion by hepatectomy.

OUTCOMES

The postoperative pathological examination revealed an IPNB with infiltrating carcinoma of the intrahepatic bile duct. This patient had an uneventful postoperative recovery and was discharged on day 21 post-surgery. Until 35 months after surgery, there is no recurrence or metastasis.

CONCLUSION

The CT and MRI can show certain morphologic features including the segmental cystic dilatation of intrahepatic bile ducts and the pathological details of papillary tumors inside the lesion. Cystic IPNB with infiltrating carcinoma of the intrahepatic bile duct can be treated with surgery.

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.

Precursors to Cholangiocarcinoma

Cancers of the biliary tract include intra- and extrahepatic cholangiocarcinomas and gallbladder cancer. Biliary tract cancers are diseases with unfavorable prognoses. In recent years, several lesions have been described as precursors that precede biliary cancers. They include flat and microscopic lesions known as biliary intraepithelial neoplasia, macroscopic and tumor-forming intraductal papillary biliary neoplasia, intraductal tubular neoplasia, and mucinous cystic neoplasm of the bile duct. These conditions are rarely diagnosed, while their natural history and progression to cancer have yet to be adequately characterized. This review examines the epidemiology, pathology, molecular biology, diagnosis, and therapy of these various precursors. Further research is required if we are to better understand this evolving field and improve the prevention and early detection of bile duct cancer.

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.

Recurrent Mutations in APC and CTNNB1 and Activated Wnt/β-catenin Signaling in Intraductal Papillary Neoplasms of the Bile Duct: A Whole Exome Sequencing Study

This study aimed to elucidate the genetic landscape of biliary papillary neoplasms. Of 28 cases examined, 7 underwent whole exome sequencing, while the remaining 21 were used for validation studies with targeted sequencing. In the whole exome sequencing study, 4/7 cases had mutations in either APC or CTNNB1, both of which belong to the Wnt/β-catenin pathway. Somatic mutations were also identified in genes involved in RAS signaling (KRAS, BRAF), a cell cycle regulator (CDC27), histone methyltransferase (KMT2C, KMT2D), and DNA mismatch repair (MSH3, MSH6, PMS1). Combined with discovery and validation cohorts, mutations in APC or CTNNB1 were observed in 6/28 subjects (21%) and were mutually exclusive. When the cases were classified into intraductal papillary neoplasms of the bile duct (IPNBs, n=14) and papillary cholangiocarcinomas (n=14) based on the recently proposed classification criteria, mutations in APC and CTNNB1 appeared to be entirely restricted to IPNBs with 6/14 cases (43%) harboring mutations in either gene. These genetic alterations were detected across the 3 nonintestinal histologic types. In immunohistochemistry, the aberrant cytoplasmic and/or nuclear expression of β-catenin was found in not only 5/6 IPNBs with APC or CTNNB1 mutations, but also 6/8 cases with wild-type APC and CTNNB1 (total 79%). In addition, APC and CTNNB1 alterations were exceptional in nonpapillary cholangiocarcinomas (n=29) with a single case harboring CTNNB1 mutation (3%). This study demonstrated recurrent mutations in APC and CTNNB1 in nonintestinal-type IPNBs, suggesting that activation of the Wnt/β-catenin signaling pathway is relevant to the development and progression of IPNBs.

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.

Intraductal papillary neoplasm of the bile duct: Assessment of invasive carcinoma and long-term outcomes using MRI

BACKGROUND & AIMS

Imaging characteristics for discriminating the malignant potential of intraductal papillary neoplasm of the bile duct (IPNB) still remain unclear. This study aimed to define the magnetic resonance (MR) imaging findings that help to differentiate IPNB with an associated invasive carcinoma from IPNB with intraepithelial neoplasia and to investigate their significance with respect to long-term outcomes in patients with surgically resected IPNB.

METHODS

This retrospective study included 120 patients with surgically resected IPNB who underwent preoperative MR imaging with MR cholangiography before surgery from January 2008 and December 2017 in two tertiary referral centers. Clinical and MR imaging features of IPNB with intraepithelial neoplasia (n = 34) and IPNB with an associated invasive carcinoma (n = 86) were compared. Regarding significant features for discriminating IPNB with or without an associated invasive carcinoma, recurrence-free survival (RFS) rates were evaluated.

RESULTS

Significant MR imaging findings for differentiating IPNB with an associated invasive carcinoma from IPNB with intraepithelial neoplasia were intraductal visible mass, tumor size ≥2.5 cm, multiplicity of the tumor, bile duct wall thickening, and adjacent organ invasion (all p ≤0.002). The 1-, 3-, and 5-year RFS rates for surgically resected IPNB were 93.8%, 79.1%, and 70.0%, respectively. RFS rates were significantly lower in patients with each significant MR imaging finding of IPNB with an associated invasive carcinoma than in those without significant MR imaging findings (all p ≤0.039).

CONCLUSIONS

MR imaging with MR cholangiography may be helpful in differentiating IPNB with an associated invasive carcinoma from IPNB with intraepithelial neoplasia. Significant MR imaging findings of IPNB with an associated invasive carcinoma have a negative impact on RFS.

LAY SUMMARY

Significant magnetic resonance imaging findings that differentiated between an intraductal papillary neoplasm of the bile duct (IPNB) with an associated invasive carcinoma and an IPNB with intraepithelial neoplasia were intraductal visible mass, tumor size ≥2.5 cm, multiplicity of the tumor, bile duct wall thickening, and adjacent organ invasion. Significant magnetic resonance imaging findings of invasive IPNB have a negative impact on recurrence-free survival.

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.

Specific risk factors contributing to early and late recurrences of intrahepatic cholangiocarcinoma after curative resection

BACKGROUND

Most intrahepatic cholangiocarcinoma (ICC) patients experienced tumor recurrences even after curative resection, but the optimal cut-off time point and the specific risk factors for early and late recurrences of ICC have not been clearly defined. The objective of the current study was to define specific risk factors for early and late recurrences of ICC after radical hepatectomy.

METHODS

Included in this study were 259 ICC patients who underwent curative surgery at our hospital between January 2005 and December 2009. Recurrences in these patients were followed-up prospectively. Piecewise regression model and the minimum P value approach were used to estimate the optimal cut-off time point for early and late recurrences. Then, Cox's proportional hazards regression model was used to identify specific independent risk factors for early and late recurrences.

RESULTS

Early and late recurrences occurred in 130 and 74 patients, respectively, and the 12th month was confirmed as the optimal cut-off time point for early and late recurrences. Cox's proportional hazards regression model showed that microvascular invasion (HR = 2.084, 95% CI 1.115-3.897, P = 0.021), multiple tumors (HR = 2.071, 95% CI 1.185-3.616, P = 0.010), abnormal elevation of serum CA19-9 (HR = 1.619, 95% CI 1.076-2.437, P = 0.021), and the negative hepatitis B status (HR = 1.650, 95% CI 1.123-2.427, P = 0.011) were independent risk factors for early recurrence, and HBV-DNA level > 10⁶ IU/mL (HR = 1.785, 95% CI 1.015-3.141, P = 0.044) and a hepatolithiasis history (HR = 2.538, 95% CI 1.165-5.533, P = 0.010) contributed to late recurrence independently.

CONCLUSION

Specific risk factors and mechanisms may relate to early and late recurrences of ICC after curative resection.

Three cases of intracystic papillary neoplasm of gallbladder

Intracystic papillary neoplasm (ICPN) of gallbladder is a comparatively new concept and is described as pre-malignant lesions in Nakanuma et al. (In: Bosman et al. (eds) WHO Classification of Tumours of the Digestive System, World Health Organization of Tumours, IARC, Lyon, 2010). ICPN with high-grade intraepithelial neoplasia is understood to include intraepithelial carcinoma or noninvasive carcinoma. And lesions with invasive cancer components are classified as ICPN with an associated invasive carcinoma [1]. According to Adsay et al., more than half of patients diagnosed with ICPN have invasive cancer components (Adsay et al., Am J Surg Pathol 36:1279-1301, 2012).Polypoid masses in the gallbladder including benign, malignant, and non-neoplastic lesions have been called gallbladder polyps, and ICPN is also a polypoid lesion in the gallbladder. However, it is difficult to differentiate between them. In the literature, it is said that the possibility of malignancy is high in lesions exceeding 1 cm (Terzi et al., Surgery 127:622-627, 2000). And there are few reports on characteristic imaging findings of ICPN.We have experienced three cases (two females and one male) of ICPN and report our imaging findings. Contrast-enhanced computed tomography revealed large papillary polypoid lesions approximately 2-4 cm in size in the gallbladder. Findings suggestive of deformation of the gallbladder wall and extrinsic progression were absent in all cases. T2-weighted magnetic resonance imaging revealed intense signals and diffusion-weighted imaging showed high intensity. Expanding of the gallbladder was seen in case 1, and a tumor stalk-like appearance was seen in the papillary mass in cases 2 and 3. Surgery was performed in all three cases and ICPN was diagnosed pathologically. The cancer was localized to the mucosa, with no infiltration of surrounding tissue in all three cases.

Gallbladder papillary neoplasms share pathological features with intraductal papillary neoplasm of the bile duct

Intraductal papillary neoplasm of the bile duct (IPNB) has been widely recognized. However, the knowledge of intracystic papillary neoplasm of the gallbladder (IPNG) including papillary adenoma and adenocarcinoma is not well defined. In this study, we compared the clinicopathological and immunohistochemical features between 32 IPNG cases and 32 IPNB cases. IPNG-1 (low-high grade dysplasia) exhibited an earlier onset age, smaller tumor size and lower level of CK20 expression compared to IPNG-2 (invasive carcinoma). Histologically, pancreaticobiliary and intestinal subtype accounted for nearly half of IPNG or IPNB (44.4% and 48.1% vs. 44.0% and 44.0%), respectively. Immunohistochemically, 88.9% of IPNG and 92.0% of IPNB cases were positive for MUC1, and 96.3% and 92.0% for CK7, respectively. CDX2 and MUC2 were more highly expressed in the intestinal subtype than in other subtypes. CK20 expression increased in parallel with tumor progression. In addition, 53.1% of IPNG cases and 68.6% of IPNB cases exhibited invasive carcinoma, and showed significant survival advantages to conventional gallbladder adenocarcinoma and cholangiocarcinoma, respectively. In conclusion, papillary adenoma and adenocarcinoma of the gallbladder can be recognized as different pathological stages of IPNG, and they share pathological features with IPNB.

A statement by the Japan-Korea expert pathologists for future clinicopathological and molecular analyses toward consensus building of intraductal papillary neoplasm of the bile duct through several opinions at the present stage

Intraductal papillary neoplasm of bile duct (IPNB) was described as a preinvasive neoplastic lesion of the biliary tract in the 2010 World Health Organization (WHO) classification. Although a number of studies have since been conducted on IPNBs, controversy remains, particularly regarding the standardization of its definition. Meetings by Japanese and Korean expert pathologists were held twice to resolve the pathological diagnostic aspects of IPNB. Through round-table discussions and histological reviews, we reached the common understanding that IPNBs diagnosed according to the criteria of WHO 2010 are characterized by intraductal predominant papillary or villous biliary neoplasms covering delicate fibrovascular stalks and are classified into two types pathologically. One type (type 1 IPNB) is histologically similar to intraductal papillary mucinous neoplasms of pancreas, and typically develops in the intrahepatic bile ducts, while the other (type 2 IPNB) has a more complex histological architecture with irregular papillary branching or with foci of solid-tubular components and typically involves the extrahepatic bile ducts. This report states the diagnostic pathologic features of IPNB proposed by WHO 2010. Since currently, the concept of IPNB is still confusing, the proposed diagnostic pathologic features stated here will be of use for future clinicopathological and molecular analyses toward consensus building of IPNB.