A stone in a grossly dilated cystic duct stump: a rare cause of postcholecystectomy pain.

We describe the unusual case of a patient who developed recurrent right upper quadrant pain 25 yr after cholecystectomy. A cystic lesion containing a calculus was identified on transabdominal ultrasound, initially suggesting the possibility of gallbladder duplication. Endoscopic retrograde cholangiography identified this lesion as a massively dilated cystic duct stump. Surgical resection led to complete resolution of symptoms. Recurrent cholelithiasis involving the cystic duct stump may lead to massive dilatation, and must be considered in the differential diagnosis of postcholecystectomy syndrome.