[Adenocarcinoma arising in congenital dilatation of the intrahepatic bile duct].

A multilocular lesion was found in the left lobe of the liver in a 70-year-old woman who had complained of jaundice, fever and tumor of epigastrium. There was a continuous and branching cystic lesion in the resected left lobe of the liver diffusely, and communication with the right hepatic duct and the extrahepatic duct was recognized. These cystic spaces were filled with bile and mucus. The inside of the wall was covered with columnar epithelium showing papillay proliferation with marked mucin production. Furthermore, adenocarcinoma was demonstrated in multifoci surrounded by hyperplastic and dysplastic epithelium. This case was diagnosed as congenital dilatation of the intrahepatic bile duct accompanying adenocarcinoma.