Intrahepatic Class VII Choledochal Cyst: Radiological Insights and Surgical Approach.

BACKGROUND Choledochal cysts are congenital cystic dilatation of any section of the bile ducts. They have been divided into 5 primary categories. This is the case of an intrahepatic variant of bile duct cysts originating from the main lobar bile ducts at the confluence, initially radiologically identified as biliary cystadenoma in segments 4b and 5. CASE REPORT A 35-year-old woman presented with right upper quadrant pain and palpable mass during examination. History and laboratory results were normal. Magnetic resonance cholangiopancreatography revealed a complicated cystic lesion compressing right and left proximal hepatic ducts, diagnosed radiologically as biliary cyst adenoma in segments 4b and 5. Intraoperatively, large cyst found in liver segment 4b and 5, extending infra-hepatic, included the confluence of the common hepatic duct and extended to the gallbladder. It was easily separable from the gallbladder, and total cholecystectomy was done; however, the cyst was inseparable from the confluence of common hepatic duct. The peritoneum over the cyst, containing the right and left hepatic duct and in the area of confluence, was dissected and pushed down to avoid injury; enucleation of the lower border was successfully done. Upper border was transected through liver parenchyma; many small ductules connected with the cyst were ligated. Resection should be done to decrease possibility of malignant transformation and prevent recurrent cholangitis. CONCLUSIONS Class VII choledochal cyst is rare, and surgery is the preferred choice, after proper evaluation of the cyst and surrounding structure. Magnetic resonance cholangiopancreatography still has a high overall accuracy for choledochal cyst diagnosis and classification.