切開・剥離法（ESD）に必要な胃癌術前診断―新しい診断法：拡大内視鏡

New Technique for Diagnosis of Gastric Cancer―Magnifying Endoscopy

要旨　拡大内視鏡を用いて胃癌の範囲診断を検討した．非癌部の胃炎拡大像は毛細血管が上皮の淵に沿って観察できたが，癌部では不規則な微細血管像として観察でき，その境界は明瞭であった．また酢酸撒布により粘膜模様がエンハンスされ，癌部は大小不同の微細な顆粒状変化を呈するなど形態的な情報も得ることが可能となった．さらに酢酸によるエンハンスは組織像によりその態度が異なり，特に分化型粘膜内癌では周囲の非癌粘膜より癌部のエンハンスが早期に消失し，癌部と非癌部のコントラストが明瞭となった．経時的に変化していくエンハンス像を観察することも可能であり，この拡大内視鏡観察をダイナミック・エンハンス拡大内視鏡と命名した．

　Subepithelial capillaries along the epithelium were regularly observed in non-cancerous epithelium and an irregular vascular system was observed in gastric cancer by magnifying endoscopy. The border between cancer and non-cancer was revealed clearly by magnifying endoscopy. Acetic acid instillation whitened the appearance of mucosa and enhanced the structure of the surface of the gastric mucosa. The appearance of cancer was observed as an irregular grain-like pattern by magnifying endoscopy with acetic acid instillation. The whitening of mucosal cancer decreased and disappeared early, although the whitening of non-cancerous epithelium remained. So, the contrast between cancer and non-cancer became clear. The whitening of adenoma remained as long as that of non-cancerous epithelium but the surface of advanced cancer was not whitened. The various whitening patterns appeared according to the differences of histology of gastric tumor. This new technique was termed dynamic enhanced magnifying endoscopy.