A Case of Carcinoma of the Gallbladder, Presenting an Intraluminal Growth, Accompanied with Partial Transverse Septum across the Organ and Anomalous Arrangement of the Pancreaticobiliary Ductal System

A 68-year-old woman was admitted to Yamanashi Medical College Hospital with chief complains of right hypochondralgia andback pain. Ultrasonography and computed tomography revealed a papillary growing tumor of the gallbladder and endoscopic retrograde cholangio pancreatography showed an anomalous arrangement of the pancreaticobiliary ductal system (AAPB). Extended cholecystectomy with dissection of the regional lymph nodes and resection of the bile duct, with biliary diversion, were performed. The resected specimen showed a partial transverse septum across the gallbladder and a cavity in the fundus occupied by a papillary growing tumor mass, of which the histological findings were papillary adenocarcinoma. The mucosa of the cavity in the neck had a normal appearance. Microscopic findings of the wall distal to the transverse septum showed proliferation of the ductal structure. Rokitansky-Aschoff sinus and dysplastic changes in the mucosa. These findings suggest that a mixture of bile and pancreatic juice caused by the AAPB and the septum was related to the pathogenesis of the gallbladder cancer in this patient.