Anomalous arrangement of pancreaticobiliary ductal system associated with cholangiocellular carcinoma

A 66-year-old man with congenital cystic dilatation of the common bile duct (CDB; Alonso-Lej Type I) and anomalous arrangement of the pancreaticobiliary ductal system (AAPB) associated with intrahepatic bile duct cancer (cholangiocellular carcinoma; CCC) underwent an extended right hepatic lobectomy. In the resected specimen, the CCC was located in Couinaud’s segment V, with invasion to segment IV and the right hepatic duct and right portal vein. However, there was no cancer involvement of the dilated extrahepatic bile ducts, except for histologic findings of chronic inflammatory cellular infiltration and intestinal metaplasia. It is presumed that the probable mechanisms underlying carcinogenesis in CCC developing from the epithelium of intrahepatic bile ducts are the same mechanisms as those operating in carcinoma of the extrahepatic bile duct in patients with AAPB, although AAPB associated with CCC is uncommon. AAPB appeared to be related to the development of the CCC.