粘膜下腫瘍の形態を示した胃癌の内視鏡診断

Endoscopic Diagnosis of Gastric Cancer Similar to Submucosal Tumors

要旨　粘膜下腫瘍の形態を呈した胃癌は10例で，切除単発胃癌の0.53％と非常にまれであった．その臨床病理学的特徴をみると，C・M領域に多く，組織型は高分化型管状腺癌，低分化腺癌の両極に分かれた．特に低分化腺癌は髄様型でlymphoid stromaを伴う傾向が強かった．内視鏡的には腫瘍中央部から偏位して存在する不整発赤，血管透見像の不整を見つけ出すことが癌の診断に重要であった．また，粘膜面の癌露出が少ないうえに，構造，細胞異型に乏しいものが存在し，生検診断に注意を要した．更に進展度診断にEUSは有用であった．

　We reviewed ten cases of gastric cancer similar to submucosal tumors with particular attention to clinicopathological and endoscopic diagnosis.

　1) The proportion of such cases was 0.53% in 1,875 patients with gastric cancer who underwent gastrectomy.

　2) Clinicopathologically, five cases were well differentiated tubular adenocarcinoma and four cases were poorly differentiated adenocarcinoma; and three of the latter cases were associated with lymphoid stroma.

　3) Endoscopically, irregular redness which shifted from the top of the tumor and/or irregularity of capillary transparency were very important indications of malignancy.

　4) Endoscopic ultrasonography was useful for the diagnosis of the depth of cancerous invasion.