Carcinosarcoma of the extrahepatic bile duct.

A rare case of a carcinosarcoma of the extrahepatic bile duct demonstrating interesting features is described. A 75-year-old woman with a history of choledocholithotomy presented with acute obstructive suppurative cholangitis. Ultrasonography and computed tomography showed a thickened choledochal wall, with calcification. Percutaneous transhepatic and endoscopic retrograde cholangiography revealed a round filling defect accompanied by an irregular obstruction in the common bile duct. Carcinosarcoma was diagnosed from a protruding lesion in the common bile duct obtained by intraoperative frozen sectioning, and pylorus-preserving pancreatoduodenectomy was performed. Histological examination by light microscopy showed a transition between the carcinomatous and sarcomatous components and positive immunoreactivity for epithelial markers in the sarcomatous component. The patient died of a local recurrence 2 years after the surgery. Polypoid growth and ossification in the tumor could be representative features of carcinosarcoma of the extrahepatic bile duct.