術前診断が困難であった小腸平滑筋肉腫の1例

Abstract

Primary neoplasms of the small intestine are unusual and constitute only 1 -5% of all gastrointestinal tract neoplasms. We report a rare case of leiomyosarcoma of the small intestine which presented preoperative diagnostic difficulties. The patient was a 63-year-old man with symptoms of tarry stools and an abdominal tumor. The tumor was fist-sized and immobile. Laboratory data showed no remarkable changes except for iron -deficiency anemia. Abdominal computed tomography and ultrasonography revealed a mass with an irregular wall and an apparent air-fluid level. Barium study showed a cavity suggesting perforation of the jdjunum. Angiography showed a tumor site in the jejunum and dilatation of the branches of the jejunal artery. During a laparotomy, the neoplasm, 10× 15 cm in diameter, was located 10cm caudad to Treiz's ligament, growing outside of the small intestinal canal. The resected specimen showed central cavitation and partial necrosis. The histological diagnosis was a leiomyosarcoma with central necrosis. In this case, the leiomyosarcoma was advanced at diagnosis. Preoperative diagnostic difficulties, frequent dissemination at the time of diagnosis, and a poor prognosis are characteristic of this disease.