[A Case of Endocrine Cell Carcinoma (small Cell Carcinoma) of Duodenum].

Extra-ampullary duodenal endocrine cell carcinoma is extremely rare. A 65-year-old woman visited our hospital, complaining of epigastralgia, anorexia and vomiting. She was admitted for suspected duodenal or pancreas head tumor by abdominal CT. Fiberscopic examination revealed a circumferential tumor in the extra-ampullary duodenal second portion. Histopathological findings of biopsy specimen showed a small cell carcinoma, and positive immunohistochemical staining for synaptophysin revealed this tumor to be endocrine cell carcinoma. Pylorus-preserving pancreaticoduodenectomy with partial transversocolectomy was performed, and intraoperative washing cytology detected tumor cells in the peritoneal cavity. Although she discharged from hospital uneventfully, she died 11 months later of multiple liver metastases and peritoneal dissemination. This case showed the high malignant potential of this tumor.