ABSTRACT
Villous adenoma of the extrahepatic duct is a rare disease. Even though it is benign, it has malignant potential and is considered a premalignant lesion. We here report one case of villous adenoma with foci of adenocarcinoma arising in the common hepatic duct. A 60-year-old male was admitted to our hospital because of epigastric pain. The cholangiogram revealed a large filling defect in the right intrahepatic and common hepatic duct with intrahepatic bile duct dilatation. The patient underwent right lobectomy. Grossly, stalked papillay tumor originated in the common hepatic duct was overriding the right intrahepatic duct. Microscopically, the tumor was composed of stratified tall columnar cells with various dysplasia and there were foci of invasive adenocarcinoma.