[A case of primary cancer of the small intestine].

We experienced the case that used S-1 for small intestinal cancer with peritoneal dissemination. A 51-year-old man admitted for fatigability and anemia. Small bowel series showed a stenosis lesion at the 15cm anal side from Treiz ligament, and the oral intestinal dilatasion was shown. CT showed the thickening of small intestinal wall and rectal wall. In addition, a rectal stenosis was shown by barium enema. It was diagnosed as small intestinal cancer with peritoneal dissemination, and an operation was performed. Peritoneal dissemination was recognized in the intraperitoneal whole, so jejunum partial resection was performed for primary cancer lesion. After an operation, internal use of S-1 was performed in an outpatient department. One course was assumed administration for four weeks and withdrawal for two weeks, and three courses was performed. There was not a side effect, and barium enema showed improvement of a rectal stenosis, and CT showed improvement of thickening of a rectal wall. A lesion worsened afterwards, and he died in postoperative six months.