空腸のgastrointestinal stromal tumor（GIST）の1例

Gastrointestinal Stromal Tumor of the Jejunum, Report of a Case

要旨　患者は55歳の女性．主訴は腹痛，黒色便．小腸X線検査でTreitz靭帯から約20cmの空腸に約3cm大の粘膜下腫瘍を認めた．側面像では腸管壁外を中心に一部粘膜面に露出する発育形態が描出された．腹部CTや血管造影，小腸内視鏡などの検査を行ったが，術前に確診は得られなかった．ただし，リンパ節転移や他臓器転移なかったため腹腔鏡アシスト下での小腸部分切除術を施行した．病理組織学的にはgastrointestinal stromal tumor (GIST)，uncommitted type，low grade malignancyと診断された．

　A 55-year-old female was admitted to the hospital because of tarry stool and anemia, but gastrofiberscopy and total colonoscopy failed to identify the bleeding focus. X-ray and endoscopic examination of the small intestine showed a submucosal tumor with erosion in the upper jejunum, measuring 3 cm in diameter. The submucosal tumor had spread to the extraluminal wall. Partial resection of the jejunum was performed in November, 1998. The tumor showed mainly expansive growth in the jejunal wall. The cut surface of the tumor was grayish white with hemorrhage. Histologically, the tumor cells consisted of round, polygonal and spindle-shaped cells. In the tumor cells, immunohistochemical analysis was positive for c-kit and CD34, negative for α-SMA, HHF-35, calponin, desmin, S-100 and neurofilament. The diagnosis of GIST of the jejunum, uncommitted-type with low grade malignancy was made. GIST of the small intestine is a rare entity and it is difficult to diagnose before operation. Neither could our case be diagnosed, and US, CT, X-ray and endoscopic examination were necessary to evaluate the tumor.