A Case of Adenosquamous Carcinoma of the Extrahepatic Bile Duct

Abstract

A 77-year-old-woman admitted for jaundice and cutaneous itching was found in abdominal computed to- mography (CT) and PTBD to have a polypoid lesion in the common bile duct confirmed by cholic cytology to be adenocarcinoma. Pancreatoduodenectomy was conducted under the diagnosis of carcinoma of the extrahepatic bile duct. The tumor consisted of an admixture of poorly differentiated adenocarcinoma and squamous cell carcinoma and was definitively diagnosed as adenosquamous carcinoma of the extrahepatic bile duct. Immunohistochemically, CAM5.2 was expressed in the adenocarcinoma component and 34βE12 in the squamous cell carcinoma component. For proliferative activity, the Ki-67 labeling index was about 70% in both components.