Double Common Bile Duct Associated With Choledochal Cyst: A Rare Developmental Anomaly.

Duplication of the extrahepatic bile duct is a highly uncommon congenital variation of biliary anatomy and may occur in conjunction with other biliary or pancreatic abnormalities. We describe the case of a 3-year-old girl who presented with abdominal discomfort and vomiting. Magnetic resonance cholangiopancreatography (MRCP) revealed a cystic lesion consistent with a choledochal cyst (CC). Intraoperatively, a double common bile duct (DCBD), an atypical anomaly characterized by duplication of the extrahepatic bile duct, was identified. Treatment involved unifying the duplicated ducts into a single channel, followed by a Roux-en-Y hepaticojejunostomy and cholecystectomy. The patient recovered well postoperatively and was advised to undergo long-term monitoring and follow-up due to potential late complications. This case highlights the importance of anticipating and recognizing rare biliary anomalies such as DCBD, as unawareness may increase the risk of intraoperative injury and underscores the need for lifelong surveillance.