胃のgastrointestinal stromal tumor (GIST) neural typeの1例

Gastrointestinal Stromal Tumor (GIST), Neural Type in the Stomach, Report of a Case

要旨　患者は41歳，女性．人間ドック時の胃内視鏡検査で胃角部大彎の胃粘膜下腫瘍を指摘された．胃X線検査では立ち上がりが急峻な約6.5cm径の半球状の腫瘍で，中央および肛門側に辺縁整で深い大小3か所の潰瘍と，病変の口側に結節状に隆起した部分を認めた．胃粘膜下腫瘍の診断のもと，幽門側胃切除術を施行した，病理組織学的には不規則な索状交錯を示す紡錐形の細胞で，一部では渦巻き状配列やpalisading示す部位も存在した．免疫組織化学的にはS-100蛋白陽性，NSE部分陽性，α-smooth muscle actin陰性などであり，更に電子顕微鏡的検索から，GIST, neural typeと診断した．

　A case of gastrointestinal tumor (GIST) neural type of stomach in a 41-year-old woman, detected by gastric endoscopy during a complete physical checkup was reported. X-ray examinations revealed a hemispheric submucosal tumor with central large ulcers, the surface of which was smooth and covered with gastric mucosa, in the greater curvature of the gastric angulus. Gastrectomy was performed. In the histological findings of the resected specimen, this tumor was showen to be composed of spindle cells, partly showing whorled or palisaded growth pattern. Immunohistochemically, tumor cells showed positive staining for S-100 protein and neuron-specific enolase (weakly), but were negative for α-smooth muscle actine. From ultrastructual evidence we conducted that it was a case of GIST, neural type.