特異な超音波像を呈した胃平滑筋腫の1例

Leiomyoma of the Stomach with Unusual Findings by Endoscopic Ultrasonography, Report of a Case

要旨　患者は51歳，男性で，人間ドックを受診し，胃X線，内視鏡検査で胃前庭部の長径約50mmの粘膜下腫瘍を指摘された．超音波内視鏡検査で腫瘤は第3層（粘膜下層）にはまり込むように存在し，低エコーの部分と無エコーの部分から成り，無エコー部は腫瘤の粘膜側に広範に存在し，低エコー部が樹林状に無エコー部に突出するように描出された．また，低エコー部と第4層（固有筋層）の連続性は認められなかった．腫瘤が大きいことや，10年前に行った検査のときに比し増大しているため手術を施行した．腫瘍は境界明瞭な45×45×20mmの半球状を呈し，腫瘍内には液体を貯溜し，腫瘤は液腔内に樹枝状に発育しており，病理学的には平滑筋腫であった．

　During a mass survey of the stomach, a 51-year-old man was found to have an elevated lesion in the antrum. Detailed examination was performed by endoscopy, which revealed a rather large submucosal tumor of the antrum. Endoscopic ultrasonography demonstrated that the submucosal tumor existed in the third layer of the gastric wall and consisted of low echoic area and echo free space. The low echoic area protruded into the echo free space which extended along the side of the mucosal layer. The low echoic area could not be demonstrated to continue to the fourth layer of the gastric wall. Partial gastrectomy was performed. In the resected stomach, there existed a submucosal tumor measuring 45×45×20 mm in size in the antrum. Pathologically, the submucosal tumor was leiomyoma of the stomach and it showed no signs of malignancy.