Cystic duct dilatation after cholecystectomy in fibropolycystic liver disease

A 50 year-old woman presented with fevers, rigors and right hypochondrial pain. On examination she was pyrexial (38.5 8C) and there was some right hypochondrial tenderness. A cholecystectomy scar was noted on the abdominal wall. A clinical diagnosis of cholangitis was made by the admitting physician. The patient had a complicated past medical history and initially presented 30 years previously at another hospital with jaundice. A liver biopsy at that time suggested a diagnosis of congenital hepatic fibrosis [1]. Over the intervening years, her history was complicated by infrequent episodes of cholangitis, but with time these episodes became more frequent. Subsequent renal imaging was consistent with medullary sponge kidneys, while hepatic imaging performed over 20 years after initial diagnosis showed a cyst in the right lobe of the liver (on ultrasound) with intrahepatic duct dilatation (at ERCP), suggestive of coexisting Caroli’s disease [2]. A further liver biopsy at that time confirmed the diagnosis of congenital hepatic fibrosis. The patient subsequently developed several episodes of cholecystitis and an interval cholecystectomy was performed 3 years prior to the current presentation. On the latest admission, a MRCP (left panel) was performed which revealed multiple small intrahepatic biliary cysts, consistent with Caroli’s disease (left panel, white arrows) with saccular dilatation of the extrahepatic biliary tree. In addition, there was a saccular cystic lesion resembling a gallbladder within the gall bladder fossa (left panel, black arrow). This called into question whether the patient had actually had a previous cholecystectomy, despite the abdominal wall scar. A subsequent multidisciplinary histopathology meeting highlighted the complete removal of the gallbladder, beyond all doubt. A review of the imaging showed that this cystic lesion, reported initially as a gallbladder, on axial T2-weighted MRI (middle panel, arrow) was indeed smaller and in a different position when compared to the pre-cholecystectomy CT scan, where the gallbladder was dilated (right panel, arrow). This saccular cyst within the gallbladder fossa on MRCP most likely represents extrahepatic biliary dilatation of the cystic duct remnant following cholecystectomy, as a consequence of Caroli’s disease. To our knowledge, this is the first case of fibropolycystic disease, where a cystic duct remnant has dilated sufficiently to be mistaken for a gallbladder, even by experienced hepatobiliary radiologists.