胃のm，sm1癌とsm2，sm3癌との鑑別―内視鏡診断の現状

Differential Diagnosis of Depth of Invasion in m, sm1 and sm2, sm3 Gastric Cancer-Present Status of Endoscopic Diagnosis

要旨　sm癌の一部まで内視鏡的粘膜切除術(endoscopic mucosal resection；EMR)の適応となることが報告されるようになった．しかし，それらの病変を術前に深達度診断可能であるかが問題である．今回はEMRの適応であるm，sm_1-α癌と適応外であるsm_1-β，sm₂，sm₃癌の内視鏡的深達度診断率について報告した．Ul(-)の2cm以下の病変においては深達度診断正診率は約90％であった．この際深達度診断は従来報告されているsmを示唆する所見を有するものをSM，それ以外をMとした．EMRを行い病理学的検索でsm_1-β以深と判明し手術を行った症例についても，その内視鏡所見と切除胃の病理組織学的所見について述べた．EMR後の病理検査でsm_1-β以深が判明したら，機を失うことなく外科的切除を行うことが重要である．

　Extensive application of endoscopic mucosal resection (EMR) to some submucosal (sm) cancers has occasionally been reported in the literature. The critical issue in this situation is whether the depth of invasion of such lesions can be determined preoperatively. This paper describes the accuracy of endoscopic diagnosis of the depth invasion of mucosal (m) and sm_1-α carcinomas, for which EMR is usually indicated, and sm_1-β, sm₂ and sm₃ carcinomas, for which EMR is not indicated. The accuracy rate of diagnosis of the depth of invasion was about 90% when evaluation was restricted to non-ulcerated lesions measuring 2 cm or less in diameter. In this evaluation, lesions having certain endoscopic features suggestive of sm carcinoma were classified under the category of SM, while other were classified as M. Endoscopic findings and histopathological findings in the resected stomach were also compared in patients who eventually underwent surgery because pathological examination following EMR revealed sm_1-β or deeper invasion. It is important to perform surgical resection without missing the opportunity if pathological examination following EMR demonstrates sm_1-β or deeper invasion.