陥凹型小胃癌の診断―通常内視鏡の立場から

Fundamental Endoscopic Findings of Depressed-Type Early Gastric Cancers Less than 10 mm

要旨　陥凹型小胃癌の基本的内視鏡所見について述べた．分化型は，不整な小陥凹として認められ，色調は基本的に発赤調を呈するが，ごく淡い発赤や褪色調を呈するものもある．形態的には，①area状の周囲隆起を伴う小星芒状陥凹，②平滑な周囲隆起を伴う小不整陥凹，③周囲隆起を伴わない小不整陥凹，の3つに大別される．一方，未分化型は，主に単発の褪色調陥凹として認められる．M癌は周囲隆起を伴わず，陥凹内に再生性の小発赤を伴うことも多い．SM癌では，粘膜下層の癌量が増すと病変全体が軽度の隆起としてとらえられる．以上の基本所見を踏まえ，詳細な観察を行う姿勢が重要である．

　Fundamental endoscopic findings of depressed-type early gastric cancers less than 10mm were reviewed. Typically, small steller reddish depression associated with surrounding rough granular elevation and spine-shaped extension was characteristic of the differentiated type of small cancers. However, some of them were recognized as small irregular reddish depressions associated with surrounding smooth elevation or without surrounding elevation. On the other hand, discolored small irregular depression without surrounding elevation was characteristic of the undifferentiated type of small mucosal cancers. They are frequently associated with reddish granular spots. Some of the undifferentiated type of small submucosal cancers are recognized as slightly elevated lesions with irregular erosion.