抄録
An asymptomatic 57-year-old woman was admitted to our hospital for further investigation of a duodenal tumor detected by screening abdominal CT. Duodenoscopy revealed an ulcerative tumor at the major duodenal papilla fistula on the longitudinal fold. A biopsy specimen from the ampullary tumor showed tubular adenocarcinoma. Endoscopic retrograde cholangiopancreatography through the fistula revealed a communication with the common bile duct. After diagnosis of ampullary carcinoma, pylorus-preserving pancreatoduodenectomy was performed. Microscopically, infiltration of cancer cells was detected beneath the normal duodenal mucosa around the fistula. According to histopathological data, the mechanism of the fistula formation was speculated to have been created by cancer invasion, explaining why this patient was not jaundiced. To our knowledge, choledochoduodenal fistulae formed by cancer invasion are rare.
