Choledochal cyst associated with polycystic kidney disease: report of a case.

We report a very rare case of type I choledochal cyst associated with a polycystic kidney disease. A 48-year-old female had been dependent on hemodialysis for chronic renal failure due to polycystic kidney disease and was incidentally diagnosed to have a dilated common bile duct by an ultrasonography. An endoscopic retrograde cholangiopancreatography showed a spindle-shaped, dilated common bile duct (type I choledochal cyst) without visualization of the pancreatic duct. She underwent a resection of the choledochal cyst. Intraoperative cholangiography showed no reflux of contrast medium into the pancreatic duct. Amylase level of the aspirated bile from the bile duct was not elevated. In the case of choledochal cyst combined with renal fibropolycystic disease, pancreaticobiliary maljunction may not contribute to the etiology of choledochal cyst. In such cases, management of choledochal cyst is still controversial and requires further discussion.