陥凹性小胃癌の診断―酢酸撒布拡大内視鏡の立場から：dynamic chemical magnifying endoscopy

Diagnosis of Small Depressive Gastric Cancer―From the Point of View of Endoscopy Using Acetic Acid : Dynamic Chemical Magnifying Endoscopy

要旨　酢酸撒布により胃粘膜は白色エンハンスされ拡大観察により粘膜パターンを詳細に診断できる．白色化は数秒で始まり，手技も簡便であり，胃癌の拡大観察には非常に有用である．さらに癌組織では非癌粘膜に比し，早期に酢酸の白色化が消退するため，癌部の範囲がさらに鮮明となる傾向がみられた．また組織像により酢酸による白色化の態度が異なった．分化型粘膜内癌では癌部の白色化が10数秒後に消退し，白色化が残る非癌部とのコントラストが明瞭であった．1cm前後の陥凹型胃癌の診断にはその存在診断，組織型，範囲診断において酢酸撒布拡大内視鏡は有用である．色素でなく，経時的変化も観察できる点からこの手技をdynamic chemical magnifying endoscopy（DCME）と筆者らは命名している．

　Gastric mucosa changed to enhancement with whitening and could be observed in detail with magnifying endoscopy after acetic acid instillation. The aceto-whitening of gastric cancerous mucosa disappeared compared to surrounding non-cancerous mucosa and the contrast of cancerous and non-cancerous mucosa became clear. The duration of aceto-whitening differed according to each histological type : aceto-whitening of well differentiated adenocarcinoma disappeared in 10～20 minutes and moderately differentiated adenocarcinoma disappeared in a few minutes. Magnifying endoscopy was very useful for detection, diagnosis of histological type and determination of the extent of gastric adenocarcinoma in small gastric cancer about 1cm in size. Endoscopy with acetic acid was not chromoendoscopy because it did not use dye and it was possible to observe changes in the whitening with time. Acetic acid-enhanced magnifying endoscopy can therefore be termed “dynamic chemical magnifying endoscopy (DCME)”.