Biliary Intraepithelial Neoplasia (BilIN) in Primary Sclerosing Cholangitis: The First Report from Iran

Genetic alterations during the neoplastic cascade towards cholangiocarcinoma in primary sclerosing cholangitis

Carcinogenesis of primary sclerosing cholangitis (PSC)-associated cholangiocarcinoma (CCA) is largely unexplored. Improved understanding of the molecular events involved may guide development of novel avenues for rational clinical management. We aimed to assess the genetic alterations during progression of the neoplastic cascade from biliary dysplasia towards CCA in PSC. Forty-four resection specimens or biopsies of PSC patients with biliary dysplasia (n = 2) and/or CCA (n = 42) were included. DNA was extracted from sections of formalin-fixed paraffin-embedded tissue blocks with dysplasia (n = 23), CCA (n = 69), and nonneoplastic tissue (n = 28). A custom-made next-generation sequencing (NGS) panel of 28 genes was used for mutation and copy number variation (CNV) detection. In addition, CNVs of CDKN2A, EGFR, MCL1, and MYC were examined by fluorescence in situ hybridization. Alterations in 16 low-grade dysplasia samples included loss of FGFR1 (19%), CDKN2A (13%), and SMAD4 (6%), amplification of FGFR3 (6%), EGFR (6%), and ERBB2 (6%), and mutations in SMAD4 (13%). High-grade dysplasia (n = 7) is characterized by MYC amplification (43%), and mutations in ERBB2 (71%) and TP53 (86%). TP53 mutations are the most common aberrations in PSC-CCA (30%), whereas mutations in KRAS (16%), GNAS (14%), and PIK3CA (9%) are also common. In conclusion, PSC-CCA exhibits a variety of genetic alterations during progression of the neoplastic cascade, with mainly CNVs being present early, whereas mutations in ERBB2, TP53, and KRAS appear later in the development of CCA. These findings are promising for the development of NGS-guided diagnostic strategies in PSC-CCA. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Characterization of high-grade biliary intraepithelial neoplasm of the gallbladder in comparison with intracholecystic papillary neoplasm

Biliary intraepithelial neoplasm (BilIN) is characterized by a microscopically identifiable preinvasive neoplasm of the biliary tract. In this study, the high-grade BilIN of gallbladder was examined pathologically and compared with the intracholecystic papillary neoplasm (ICPN) of gallbladder. Sixteen high-grade BilINs (height <0.5 cm) collected from 2297 cholecystectomies (0.7%) and another three cases (19 cases total) were examined and compared with 34 cases of ICPN (greatest diameter ≥1 cm and height ≥0.5 cm). High-grade BilINs were incidentally found in 11 cholecystectomies, and the remaining eight were cholecystectomized in cases with a preoperative diagnosis of carcinoma. The largest diameter ranged from 0.5 to 6 cm. While 13 cases were recognized grossly as clustered granular and rough mucosa, the remaining were almost unrecognizable. Histologically, the high-grade BilINs showed intraepithelial neoplastic growth. Furthermore, they frequently showed intraepithelial replacement growth to non-neoplastic glands and cystic lesions in the gallbladder. The lesions presented with flat, wave or fold-like patterns, including tubular components. Short papillary components were also found in 13 cases. Gastric and biliary subtypes were frequent. Several foci of stromal invasion were found in the short papillary components in three cases. The lower polypoid or granular parts of conglomerated ICPNs showed intraepithelial neoplastic lesions sharing many features with high-grade BilINs with short papillary components. In conclusion, high-grade BilINs showed intraepithelial growth of neoplastic epithelia involving the mucosa. A morphologic continuum was noted between high-grade BilINs with short papillary components and conglomerated ICPNs, suggesting that conglomerated ICPNs may arise from high-grade BilINs with short papillary components.

Intraductal papillary mucinous neoplasm of the biliary tract with cardiac metastasis: A case report

INTRODUCTION

Intraductal papillary mucinous neoplasm of the biliary tract (IPNB) is a rare, low-grade neoplasm limited to the bile duct mucosa. The malignant transformation rate is low, and there have been limited reports of metastasis to other organs. Herein, we presented a rare case of a patient who was diagnosed with IPNB concurrent with invasive adenocarcinoma after surgery and was diagnosed with cardiac metastasis 6 months later.

PATIENT CONCERNS

A 61-year-old male patient presented with abdominal pain to a local clinic. He was diagnosed with intrahepatic cholangiocarcinoma with pancreatitis and transferred to our hospital.

DIAGNOSIS

Diagnostic testing (magnetic resonance imaging, endoscopic retrograde cholangiopancreatography, positron emission tomography-computed tomography) revealed a papillary neoplasm and invasive adenocarcinoma with papillary neoplasm in the periampullary lesion.

INTERVENTIONS

Pancreaticoduodenectomy, right hemihepatectomy, and left lateral sectionectomy of the liver were performed. After surgery, we planned gemcitabine-based adjuvant chemotherapy.

OUTCOMES

Upon completion of the sixth gemcitabine chemotherapy cycle, a hyperechoic, oval-shaped mass (1.3 × 2.6 cm) was found on the outer wall of the right atrium. Resection of a cardiac tumor in the right atrium and patch repair were performed.

CONCLUSION

To our knowledge, no other case of cardiac metastasis found during observation after surgery for an IPNB has been described. IPNBs are known to be less aggressive and to have a lower metastasis rate than intraductal papillary mucinous neoplasms; therefore, the number of case reports describing metastasis after surgery is relatively low. Our case suggests that close observation is necessary in patients diagnosed with an IPNB.

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.

Biliary Intraepithelial Neoplasia in Non-biliary Cirrhosis-Report From 100 Explanted Livers: A Single Center Experience

Background:

Intrahepatic cholangiocarcinoma is a highly malignant tumor with a very short 5-year survival. Multistep carcinogenesis has been suggested as the main pathway for the development of this tumor. Main suggested precursors have been (1) biliary intraepithelial neoplasia (BilIN) and (2) intraductal papillary neoplasm of bile duct (IPNB). The former is flat and does not produce grossly and radiologically detectable mass lesion, but the latter produces grossly identifiable lesion.

Objectives:

The development of bile duct dysplasia (BilIN) in chronic biliary diseases has been investigated and proved, but the incidence of BilIN in non-biliary causes of cirrhosis such as hepatitis B and non-alcoholic steatohepatitis has very rarely been investigated. In this study, we have tried to find out the prevalence of BilIN in non-biliary cirrhosis.

Patients and Methods:

During the study period (2017-2018) in 100 explanted livers with the diagnosis of non-biliary cirrhosis, thorough sampling (at least 20 sections) was performed, and pathologic sections were studied for the presence of BilIN.

Results:

In the 100 studied livers with different diagnoses of non-biliary causes of cirrhosis, 31% of cases showed BilIN-1 and 2% of cases showed BiliIN-2. No case of BilIN-3 has been identified.

Discussion and Conclusions:

Non-biliary causes of cirrhosis should be considered as precursors of cholangiocarcinoma (BilIN); however, the incidence of this occurrence is low.

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.