Congenital bile duct cysts: Classification, operative procedures, and review of thirty-seven cases including cancer arising from choledochal cyst.

Congenital bile duct cysts are observed in any part of the bile duct from the liver to the duodenum. Reports of cases of cancer arising from it are increasing. Excision of the choledochal cyst seems to be the treatment of choice and partial resection of the intrahepatic cyst followed by intrahepatic cystoenterostomy at the porta hepatis is necessary for type IV-A cysts.