三次元超音波内視鏡が深達度診断に有用であったsm小浸潤胃癌の1例

Early Gastric Cancer, in which Three Dimensional Endoscopic Ultrasonography Influenced the Choice of Treatment, Report of a Case

要旨　今回われわれは，治療法の選択に術前精査としての三次元超音波内視鏡が有用であった早期sm胃癌の1例を経験したので報告した．患者は，54歳，男性．人間ドックの上部消化管造影検査で前庭部の浅い陥凹を指摘され来院した．内視鏡検査でも同様に約1cm大の不整形の発赤する伸展良好な浅い陥凹性病変が認められ，粘膜切除術を含めた治療法の選択が考慮されていたが，三次元超音波内視鏡により第3層のわずかな狭小化所見を認めsm浸潤が疑われ，幽門側胃切除術およびリンパ節郭清術D2が施行された．病理組織学的検討では，三次元超音波内視鏡が指摘した部位に576μmの浸潤が認められた．当院におけて三次元超音波内視鏡を術前施行した148例の深達度診断正診率は，全体で85.1％（126/148）であり，特にm，sm癌の成績が93.2％，81.4％と良好であった．更に，sm浸潤度別の成績では三次元超音波内視鏡は，500μmを超える群より80％を超える成績が得られており，粘膜切除術前の検査として有用と考えられた．

　An abnormality in 51-year-old male was pointed out in an upper gastrointestinal barium meal examination during a health check, and the man visited our hospital. Endoscopy revealed a shallow depressed lesion with irregular margin in the greater curvature of the antrum. Three dimensional endoscopic ultrasonography (3D-EUS) was able to detect a minute narrowing of the third layer which meant submucosal invasion. Therefore the patient was referred to surgery instead of endoscopic treatment such as endoscopic mucosal resection (EMR). The minute submucosal invasion detected by 3D-EUS was confirmed histologically. From November,1994 up to now, we have performed 3D-EUS in 148 patients with gastric cancer. The accuracy of 3D-EUS for diagnosing the depth of gastric cancer is 93.2% (82/88) in intramucosal cancer,81.4% (35/43) in submucosal,0% (0/2) in proper muscle,63.6% (7/11) in subserosal,66.7% (2/3) in serosal,0% (0/1) in si (T4) respectively, and totally 85.1% (126/148). Concerning of the accuracy of 3D-EUS according to the degree of submucosal invasion,3D-EUS was able to detect minute submucosal invasion (more than 500 μm vertical invasion) with 80% or more accuracy.

　We concluded that 3D-EUS is useful for evaluating early gastric cancer, especially for determining whether endoscopic mucosal resection is indicated or not.