小腸悪性腫瘍の診断と治療―GIST

Diagnosis and Treatment of Small Intestinal GIST

要旨　小腸GISTの臨床病理学的特徴について，胃GISTとの比較を中心に述べた．小腸GISTは胃GISTと比較して，腫瘍径が大きく，術前生検採取が難しい．組織所見としては紡錘形が多く，遺伝子については，c-kit exon 9変異の頻度が高く，c-kit exon 11変異の頻度は低いという特徴がみられた．また，NF1の患者に合併しやすく，術後再発率が高く，予後不良であった．小腸GISTを術前に確定診断することは困難なことが多いため，CT，小腸内視鏡，小腸X線造影などの精査で小腸GISTの可能性が疑われたときは，安易に経過観察せずに外科治療を選択することが重要である．

　We described clinicopathological features of small intestinal GIST（sGIST）comparing with those of gastric GIST（gGIST）. In comparison with gGIST, features of sGIST were as follows ; size was larger, preoperative biopsy was technically more difficult, spindle-shaped type was histologically more frequent, KIT exon 9 mutation was more frequent, KIT exon 11 mutation was less frequent, NF1 patients were more frequently complicated with sGIST than gGIST, probability of postoperative recurrence was higher, and prognosis was worse. If a patient was suspected of sGIST after investigation of CT, endoscopy or contrast study of small intestine, a surgical therapy is preferred rather than a wait-and-see policy.