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

Abstract

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.

Keywords: Biliary; Common; Pancreatic; Preneoplastic; Progenitors; Tumor.

Figure 1

Common and Distinctive Features of peribiliary and pancreatic ductal glands. The peribiliary glands are tubule-alveolar glands present within the walls of larger biliary ducts, more commonly located at branching points of the biliary tree, in particular at the hepatopancreatic region. The pancreatic ductal glands containing pancreatic committed progenitors are observed within the walls of larger pancreatic ducts. PBGs: Peribiliary glands; PDGs: Pancreatic ductal glands.

Figure 2

Common and distinctive features of pancreatic intraepithelial neoplasias and biliary intraepithelial neoplasms. A: Pancreatic intraepithelial neoplasia, high grade (PanIN-3, 10 ×) sorrounded by infiltrating adenocarcinoma. B: Biliary intraepithelial neoplasia, high grade (BilIN-3, 10 ×) with nearby infiltrating adenocarcinoma Both lesions are microscopic precancerous lesions of pancreas (A) and biliary tree (B), not identifiable by radiological imaging.

Figure 3

Common and distinctive features of pancreatic and biliary intraductal papillary mucinous neoplasms. Low power view of intraductal papillary mucinous neoplasm of the pancreas (A) with oncocytic aspects (B), causing evident dilatation of the Wirsung duct which was detected radiologically as a macroscopic lesion. Low power view of intraductal papillary neoplasm of the bile duct (C) characterized by a polypoid growth inside the common hepatic duct, composed of multiple papillary projections with a fibrovascular stroma and covered by oncocytic cells (D). In the upper left part of panel D at higher magnification, the transition between the normal bile duct epithelium and the papillary neoplastic proliferation is evident.