Extensive biliary intraepithelial neoplasia (BilIN) and multifocal early intrahepatic cholangiocarcinoma in non-biliary cirrhosis

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.

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.

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.

Anatomical, histomorphological and molecular classification of cholangiocarcinoma

Cholangiocarcinoma constitutes a heterogeneous group of malignancies that can emerge at any point of the biliary tree. Cholangiocarcinoma is classified into intrahepatic, perihilar and distal based on its anatomical location. Histologically, conventional perihilar/distal cholangiocarcinomas are mucin-producing adenocarcinomas or papillary tumours; intrahepatic cholangiocarcinomas are more heterogeneous and can be sub-classified according to the level or size of the displayed bile duct. Cholangiocarcinoma develops through multistep carcinogenesis and is preceded by dysplastic and in situ lesions. Definition and clinical significance of precursor lesions, including biliary intraepithelial neoplasia, intraductal papillary neoplasms of the bile duct, intraductal tubulopapillary neoplasms and mucinous cystic neoplasm, are discussed in this review. A main challenge in diagnosing cholangiocarcinoma is the fact that tumour tissue for histological examination is difficult to obtain. Thus, a major clinical obstacle is the establishment of the correct diagnosis at a tumour stage that is amenable to surgery which still represents the only curable therapeutic option. Current standards, methodology and criteria for diagnosis are discussed. Cholangiocarcinoma represents a heterogeneous tumour with regard to molecular alterations. In intrahepatic subtype, mainly two distinctive morpho-molecular groups can currently be discriminated. Large-duct type intrahepatic cholangiocarcinoma shows a high mutation frequency of oncogenes and tumour suppressor genes, such as KRAS and TP53 while Isocitrate Dehydrogenase 1/2 mutations and Fibroblast Growth Factor Receptor 2-fusions are typically seen in small-duct type tumours. It is most important to ensure the separation of the given anatomical subtypes and to search for distinct subgroups within the subtypes on a molecular and morphological basis.

Kupffer Cell-Derived Tnf Triggers Cholangiocellular Tumorigenesis through JNK due to Chronic Mitochondrial Dysfunction and ROS

Intrahepatic cholangiocarcinoma (ICC) is a highly malignant, heterogeneous cancer with poor treatment options. We found that mitochondrial dysfunction and oxidative stress trigger a niche favoring cholangiocellular overgrowth and tumorigenesis. Liver damage, reactive oxygen species (ROS) and paracrine tumor necrosis factor (Tnf) from Kupffer cells caused JNK-mediated cholangiocellular proliferation and oncogenic transformation. Anti-oxidant treatment, Kupffer cell depletion, Tnfr1 deletion, or JNK inhibition reduced cholangiocellular pre-neoplastic lesions. Liver-specific JNK1/2 deletion led to tumor reduction and enhanced survival in Akt/Notch- or p53/Kras-induced ICC models. In human ICC, high Tnf expression near ICC lesions, cholangiocellular JNK-phosphorylation, and ROS accumulation in surrounding hepatocytes are present. Thus, Kupffer cell-derived Tnf favors cholangiocellular proliferation/differentiation and carcinogenesis. Targeting the ROS/Tnf/JNK axis may provide opportunities for ICC therapy.

Pathology of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCC) is a primary carcinoma of the liver with increasing significance and major pathogenic, clinical and therapeutic challenges. Classically, it arises from malignant transformation of cholangiocytes bordering small portal bile duct (BD) to second-order segmental large BDs. It has three major macroscopic growth pattern [mass-forming (MF), periductal infiltrative (PI), and intraductal growth (IG)] and histologically is a desmoplastic stroma-rich adenocarcinoma with cholangiocyte differentiation. Recent data pointed out noteworthy degree of heterogeneity in regards of their epidemiology and risk factors, pathological and molecular features, pathogenesis, clinical behaviors and treatment. Notably, several histological variants are described and can coexist within the same tumor. Several different cells of origin have also been depicted in a fraction of iCCs, amongst which malignant transformation of ductules, of hepatic stem/progenitor cells, of periductal glands or through oncogenic reprogramming of adult hepatocytes. A degree of pathological overlap with hepatocellular carcinoma (HCC) may be observed in a portion of iCC. A series of precursor lesions are today characterized and emphasize the existence of a multistep carcinogenesis process. Overall, these new data have brought up in proposal of new histological or molecular classifications, which could soon replace current anatomic-based classification and could have major impact on establishment of prognosis and on development of novel target treatment approaches.

Malignant Transformation in Von-Meyenburg Complexes: Histologic and Immunohistochemical Clues With Illustrative Cases

Benign developmental defects known as Von-Meyenburg complexes (VMCs) have been postulated to progress to cholangiocarcinoma (CC) in rare instances. Although a gradual, sequential histologic transition from VMCs to CC has been described in some of these cases, the underlying genetic mechanism is yet to be elucidated. Here, we review the literature to put together a report on the clinicopathologic features and immunohistochemical changes associated with such transformation. We also review the documented association between CC and p16 inactivation, and discuss a possible role for this mechanism to contribute in VMCs to CC progression. In addition, using 2 illustrative cases encountered at our institute, we provide morphologic and immunohistochemical clues that can be used to detect such progression from hamartoma to malignancy. These cases and the accompanying review of literature further solidify the association between VMCs and CC.

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.

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.

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.

Preneoplastic conditions underlying bile duct cancer

BACKGROUND

Malignancies arising from the biliary tract can arise from the epithelial lining of the biliary tract and surrounding tissues. Conditions that predispose to malignancy as well as preneoplastic changes in biliary tract epithelia have been identified. In this overview, we discuss preneoplastic conditions of the biliary tract and emphasize their clinical relevance.

RESULTS

Chronic biliary tract inflammation predisposes to cancer in the biliary tract. Biliary tract carcinogenesis involves a multistep process as a consequence of chronic biliary epithelial injury or inflammation. Reminiscent of other gastrointestinal epithelial malignancies such as gastric, colon, and pancreatic cancer, biliary tract cancers may evolve via multistep progression from epithelial hyperplasia and dysplasia to malignant transformation. The potential role of initiating cells is also becoming recognized.

CONCLUSIONS

In spite of improved risk factor recognition, and advances in diagnostic tools, the early diagnosis of pre-malignant or malignant biliary tract conditions is extremely challenging, and there is a paucity of evidence on which to base their management. As a result, the role of pre-emptive surgery remains largely undefined.

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.

Primary sclerosing cholangitis patients with serial polysomy fluorescence in situ hybridization results are at increased risk of cholangiocarcinoma

OBJECTIVES

A polysomy fluorescence in situ hybridization (FISH) result in a pancreatobiliary brushing from a patient with primary sclerosing cholangitis (PSC) is very worrisome for carcinoma. However, treatment is not recommended unless verified by corroborative evidence of malignancy because of less than perfect test specificity in this population. The aim of this study was to evaluate the clinical outcome of PSC patients with serial polysomy FISH results.

METHODS

Patients with PSC underwent endoscopic retrograde cholangiopancreatography with brushings when clinically indicated per standard practice. Brushings were evaluated by routine cytology and FISH. Retrospective review identified patients with a polysomy FISH result without definitive imaging or pathological evidence of malignancy at the time of the first polysomy, who underwent follow-up examinations including subsequent FISH testing (n=30). Patient records were reviewed to determine clinical outcome.

RESULTS

In all, 9 of 13 patients (69%) with a subsequent polysomy result (i.e., serial polysomy) were diagnosed with cholangiocarcinoma (CCA) compared with 3 of 17 patients (18%) with subsequent non-polysomy results (P=0.008). There was a significant difference in time to a diagnosis of CCA between PSC patients with serial polysomy compared with those with subsequent non-polysomy (P=0.01). In four patients with serial polysomy results, imaging/pathological evidence of CCA was not found until 1-2.7 years after the initial polysomy FISH result.

CONCLUSIONS

FISH may detect polysomic cells in pancreatobiliary brushings before other pathological or imaging techniques identify CCA. Patients with serial polysomy FISH results are at higher risk for having CCA than those with subsequent non-polysomy FISH results.

Surgical outcomes of multicentric adenocarcinomas of the biliary tract

OBJECTIVE

In comparison to single biliary cancers, distinct features of biliary multicentric adenocarcinomas are not yet clear.

METHODS

From July 1992 to July 2009, 393 patients underwent surgery for cancers of the biliary tract at the National Cancer Center Hospital East, Kashiwa, Japan. Clinicopathological characteristics and surgical outcomes of multicentric biliary adenocarcinoma were compared with those of single cancers.

RESULTS

During the period, 10 cases (2.5%) with multicentric cancer (6 synchronous and 4 metachronous cancers) were found among 393 cases of biliary cancer. Pathologically, compared with single cancers, multicentric adenocarcinomas were more likely to be early cancers and to be papillary carcinomas with both superficial epithelial tumor spread and extensive dysplastic epithelium, but were less likely to have lymph node metastases (P < 0.01). The proportion of multicentric cancers among early papillary cancers was high (9/24, 37.5%). Clinically, no recurrences were detected in lymph nodes, peritoneum or distant organs, but one recurrence in the remnant bile duct. Only one patient died from cancer progression. The overall survival of patients with multicentric adenocarcinomas was statistically the same as that of single cancers (median survival: 69 vs. 30 months, P = 0.47).

CONCLUSIONS

Multicentric adenocarcinomas of the biliary tract have distinct features compared with single cancers.

Intraductal papillary neoplasm of the bile duct in liver cirrhosis with hepatocellular carcinoma

A case of intraductal papillary neoplasm of the bile duct (IPNB) arising in a patient with hepatitis B-related liver cirrhosis with hepatocellular carcinoma (HCC) is reported. A 76-year-old man was admitted to our hospital with recurrent HCC. Laboratory data showed that levels of carcinoembryonic antigen and carbohydrate antigen 19-9 were elevated. He died of progressive hepatic failure. At autopsy, in addition to HCCs, an intraductal papillary proliferation of malignant cholangiocytes with fibrovascular cores was found in the dilated large bile ducts in the left lobe, and this papillary carcinoma was associated with an invasive mucinous carcinoma (invasive IPNB). Interestingly, extensive intraductal spread of the cholangiocarcinoma was found from the reactive bile ductular level to the interlobular bile ducts and septal bile ducts and to the large bile ducts in the left lobe. Neural cell adhesion molecule, a hepatic progenitor cell marker, was detected in IPNB cells. It seems possible in this case that hepatic progenitor cells located in reactive bile ductules in liver cirrhosis may have been responsible for the development of the cholangiocarcinoma and HCC, and that the former could have spread in the intrahepatic bile ducts and eventually formed grossly visible IPNB.