抄録
A 40-years-old woman came to our hospital for further evaluation of the dilatation of the common bile duct. Endoscopic retrograde cholangiopancreatography showed cystic dilatation of the common bile duct and pancreaticobiliary maljunction (PBM) with a 16-mm long common channel. Two narrow-branches were derived from the long common channel. The patient was diagnosed as congenital dilatation of the bile duct (Totani ClassificationIa) , and underwent laparoscopic bile duct resection and bilioenteric anastomosis. Histologically, there were no neoplastic lesions. Pathogenesis of PBM is not be fully elucidated. Side branches are derived from the long common channel in some PBM cases, which suggests that the long common channel in PBM is derived from the pancreatic duct.