Common bile duct duplications represent exceptionally rare congenital anomalies of the biliary tract. In this case report we document an unusual variant of common bile duct duplication in a 79-year-old man who underwent a pancreaticoduodenectomy for ampullary cancer. The duplication consisted of two unseparated, completely-layered, common bile ducts which originated above the cystic duct junction and terminated prior to the point of insertion into the pancreas, where the two lumens converged into a single duct. Duplication of the bile duct is rare and often goes undetected. In the present case, the anomaly was found incidentally in a patient who had a pancreaticoduodenectomy for an ampullary carcinoma. However, duplication may be associated with choledocholithiasis, cholangitis, pancreatitis, and pancreaticobiliary malignancies and it is important to be aware of the condition.
Keywords: ampullary carcinoma; common bile duct; computed tomography; duplication; pancreaticoduodenectomy.