Double common bile duct - A rare case report and review of literature

INTRODUCTION: Extrahepatic bile duct duplication is an extremely rare congenital anomaly. There are five different types of this malformation. Due to unusual anatomy, the bile duct can be damaged during surgery. We herein report a case of double common bile duct and review the literature about this uncommon anatomical variation. CASE PRESENTATION: A 72-year-old female was diagnosed with hepatic flexure colon cancer cT4bN1M0. The tumor invaded the pancreatic head and D2 duodenum in abdomen CT-scan. She underwent an en-bloc extended right hemicolectomy with duodenopancreatectomy and lymph node dissection. During surgery, we discovered that the cystic duct did not open into the common bile duct and there two parallel extrahepatic bile ducts merging into a single duct before draining into the D2 duodenum. DISCUSSION: Bile duct duplication is an extremely rare congenital variation and has only been reported in the literature as clinical cases. According to Choi, there were five types of these anomalies, our clinical case was classified as type V of this classification. CONCLUSION: We presented a case of double common bile duct discovered incidentally during surgery. The surgeons need to carefully expose the extrahepatic biliary tract to avoid bile duct injury.