Spindle cell-type undifferentiated carcinoma of the common bile duct of the hepatic hilus: report of a case.

Spindle cell-type undifferentiated carcinoma arising from the extrahepatic bile duct is extremely rare. We herein report a case of this type of carcinoma in the common bile duct of the hepatic hilus. A 59-year-old man was admitted to our hospital complaining of jaundice. The laboratory data revealed an elevation of the serum carbohydrate antigen 19-9 level. Cholangiography revealed a complete obliteration of the left hepatic bile duct and stenosis of the bile duct from the superior to the right hepatic bile duct. Computed tomography showed the tumor to measure 15 x 12 mm in the hepatic hilus, with the obliteration of the right to main trunk of the portal vein and a swollen lymph node in the hepato-duodenum ligament. Arteriography revealed a kink of the right hepatic artery; therefore an encasement of the right hepatic artery was suspected. We preoperatively diagnosed hilus bile duct carcinoma and scheduled a right trisection hepatectomy. Intraoperative frozen sections taken from the tumor and tissues around the hepatic arteries showed spindle and inflammatory cells; therefore an inflammatory pseudotumor was diagnosed intraoperatively. As the right hepatic bile duct was occluded, a right lobe hepatectomy was performed. However, a permanent section revealed both spindle cells and poorly differentiated tubular adenocarcinoma cells positive for CAM5.2, AE1/AE3, and vimentin. On the basis of these findings, the tumor was finally diagnosed to be spindle cell-type undifferentiated carcinoma. Unfortunately, the patient died of pulmonary infarction 11 days after the operation.