早期胃癌診断の実際―微小胃癌・小胃癌：内視鏡所見

Endoscopic Fundamental Findings of Minute or Small Gastric Cancers

要旨　微小・小胃癌の内視鏡所見を形態別に述べた．陥凹型分化型癌は，不整な小発赤陥凹としてみられる．典型的なものはarea状の周囲隆起および棘状の延び出しを伴う小星芒状陥凹としてみられるが，平滑な周囲隆起を伴う小不整陥凹，あるいは周囲隆起を伴わない小不整陥凹としてみられるものもある．たこいぼ胃炎，治癒期びらんとの鑑別が必要である．陥凹型未分化型癌は，周囲隆起を伴わない褪槌色調の小不整陥凹としてみられ，陥凹内に再生性小発赤顆粒を伴うことが多い．胃底腺領域内の限局性萎縮，悪性リンパ腫（特にMALTリンパ腫）との鑑別を要する．隆起型は基本的に分化型を呈し，境界明瞭な淡赤色～褪色調の小隆起としてみられる．腺腫，疣状胃炎との鑑別が必要である．微小・小胃癌の発見には，軽微な異常所見を見逃さないと同時に正確な生検技術が要求される．

　Endoscopic fundamental findings of minute or small gastric cancers were reviewed.

　1) Depressed type minute or small gastric cancers; Typically, small stellar reddish depression associated with surrounding rough granular elevation and spineshaped extension was characteristic of the differentiated type of minute or small cancers. Though, 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 minute or small cancers. They are frequently associated with reddish granular spots.

　2) Protruding-type minute or small gastric cancers; Slight reddish or discolored small elevation with clear margin was characteristic of the protruding-type minute or small gastric cancers. Most of them were differentiated type adenocarcinoma.

　3) Care must be taken to detect slight abnormalities, and accurate biopsy is required, so that minute or small gastric cancers are not overlooked.