[A case of synchronous cancer of the gall bladder, common bile duct, and the papilla of vater].

A 58-year-old man was diagnosed with liver dysfunction during a health exam and subsequently visited a doctor. Abdominal ultrasonography revealed space-occupying lesions in the gall bladder and bile duct, and he was hospitalized for further examination and treatment. Computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), and magnetic resonance cholangiopancreatography (MRCP) revealed double cancer of the gall bladder and bile duct with pancreaticobiliary maljunction (PBM), and we performed a pancreatoduodenectomy. Pathological examination revealed gall bladder and bile duct cancer, and severe dysplasia of the papilla of Vater. We diagnosed synchronous triple cancer because none of the cancers had continuity or vascular invasion. Each cancer was at Stage I, and the patient has survived for 2 years and 6 months without recurrence and no additional treatment. PBM is a mutation of the junction of the pancreatic and bile ducts outside of the duodenal wall, and is a known complication of biliary tract cancer due to the reflux of pancreatic juice and bile. Because K-ras and p53 gene mutations occur in the biliary tract mucosal epithelium, PBM increases the risk of developing multicentric cancer. It is important to consider the existence of double cancer when biliary tract cancer is detected in a PBM patient.