Type II congenital biliary dilation (biliary diverticulum) with pancreaticobiliary maljunction successfully treated by laparoscopic surgery: report of a case

Biliary diverticulum or type II congenital biliary dilation accounts for only 1-2% of all patients with congenital biliary dilation. The association between pancreaticobiliary maljunction (PBM) and this type of anomaly remains unclear. A 40-year-old Japanese woman presented with a history of repeated upper abdominal pain for more than 30 years. Computed tomography showed a cystic lesion (diameter 30 mm) arising from the common bile duct. Magnetic resonance cholangiopancreatography revealed a biliary diverticulum (diameter 33 mm) and the cystic duct entering the diverticulum. There was no dilation of the intrahepatic or extrahepatic ducts. Endoscopic retrograde cholangiopancreatography demonstrated PBM. A diagnosis of type II biliary diverticulum with PBM was made, and the patient underwent laparoscopic resection of the diverticulum combined with cholecystectomy. Pathological examination of the resected specimen showed slight inflammation, but no malignancy in the diverticulum or gallbladder. The patient's postoperative course was uneventful. To our knowledge, this is the first report of successful laparoscopic resection of biliary diverticulum associated with pancreaticobiliary maljunction.