5) Barrett食道癌の拡大内視鏡診断

Magnifying Endoscopy for Superficial Barrett's Esophageal Cancer

要旨　欧米では食道癌の過半数はBarrett食道癌だが大部分が進行癌であるため，その初期像は明らかにされていない．本稿では自験例をもとに，Barrett表在癌の拡大内視鏡所見を解説した．Barrett食道を拡大観察する際に注目すべきは表面構造と血管構造である．表面構造の観察には通常観察のみならずインジゴカルミン撒布や酢酸撒布が有用である．表面構造はpitとvilliに大別され，癌部ではpitやvilliの高密度化，不整化，融合所見が認められる．血管構造の観察にはNBIが有用であり，走行異常，血管長の伸張，口径不同，不整分岐，network patternの有無が鑑別のポイントとなる．

　Observation with the magnifying endoscopy is sometimes difficult because the range of focus is very narrow and the visual field is very small. However, the surface pit pattern and micro vascular pattern were able to be observed with magnifying endoscopy and they gave us a lot of useful information for the diagnosis of superficial Barrett's esophageal neoplasia.

　The surface pattern were able to be classified as pit and villi. The pit and villi of cancer is more irregular than non-neoplastic mucosa, and the villi of cancer sometimes fuse with each other. The other important point of magnifying endoscopic diagnosis is vascular irregularity. Not only the shape of micro vessels but also the caliber of the vessels is irregular. Therefore, both surface pattern and micro vessels should be observed for early detection of superficial Barrett's esophageal cancer.

　A typical surface pattern and micro vascular pattern are shown in Fig. 1 to Fig. 8.