RESUMEN
A 62-year-old woman was admitted for epigastralgia, nausea and tarry stool.Abdominal CT showed a tumor to the jejunum from the duodenum, and peritoneal dissemination.Gastroduodenoscopy showed a type 2 tumor, and the histopathological examination revealed a well-to moderately-differentiated adenocarcinoma.Accordingly, she was diagnosed with primary adenocarcinoma of the small intestines and underwent surgery.The first-line chemotherapy with S-1/CPT-11 was started after surgery, and the tumor marker returned to normal.The treatment of 14 courses was continued until PD due to the enlargement of the peritoneal dissemination.Second - and third-line chemotherapy were performed; however, she died 20 months after the initial treatment.Although the incidence of primary adenocarinoma of the small intestines is relative- ly low, and there is no established chemotherapy at present, this case suggested that S-1/CPT-11may be an effective regimen for advanced primary adenocarcinoma of the small intestines.