[A Case of Long-Term Survival in a Patient with Small Intestinal Adenocarcinoma with Peritoneal Dissemination].

Primary small intestinal adenocarcinoma is rare and its outcome is poor. A 46-year-old man admitted for vomiting was found in enhanced abdominal CT to have local jejunum stenosis and dilation at its oral site. A partial jejunectomy was performed and a jejunal tumor with multiple disseminated nodules in the peritoneum was revealed. Histologically, the adenocarcinoma of the jejunum appeared to be a papillary adenocarcinoma, and also, in part, a moderately differentiated tubular adenocarcinoma. After the jejunectomy, the patient was treated with S-1 chemotherapy, but 22 months after the initial diagnosis, a recurrence was detected. The patient underwent a second partial jejunectomy, and a weekly dose of paclitaxel (PTX) plus doxifluridine (5'-DFUR) was selected as the second-line treatment. The patient is still responding to the treatment 55 months after the last operation. Combination chemotherapy with weekly PTX/5'-DFUR may improve the prognosis for S-1-resistant small intestinal adenocarcinoma.