Cystic duct remnant carcinoma with widespread invasion along the extrahepatic bile duct wall: dynamic CT findings.

We report a case of remnant cystic duct carcinoma with widespread invasion along the common bile duct wall. Thin-slice dynamic computed tomography showed circumferential wall thickening of the extrahepatic bile duct (from the common hepatic duct to the intrapancreatic common bile duct) and the remnant cystic duct. Pathologically, the extrahepatic bile duct wall was thickened due to submucosal tumor infiltration by cystic duct papillary adenocarcinoma.