表在型食道扁平上皮癌の拡大内視鏡診断

Superficial Esophageal Squamous Cell Carcinoma Diagnosed Using Magnified Endoscopy with Narrow Band Imaging

要旨●日本食道学会分類^1）〜3）は，Inoue^4），Arimaら^5）の分類を基盤として，より簡略化したもので，表在型扁平上皮癌の深達度診断を主目的としている．簡便な分類であるにもかかわらず，深達度診断に有用であり，広く普及している．一方で，その限界も明らかにされつつあるため，本稿では日本食道学会分類の現状と課題に関して解説した．

　A new system of magnified endoscopic classification of superficial esophageal squamous cell carcinoma was established by the Japan esophageal association. The micro vascular pattern was classified into B1, loop like vessels ; B2, non-loop vessels ; and B3, vessels that are three times or more thicker than B2. B1, B2, and B3 correspond to T1aEP or LPM, T1aMM or T1bSM1, and T1bSM2, respectively.

　Avascular area surrounded by B2 vessels was classified on the basis of their diameters into AVA-S（<0.5mm）, M（0.5〜3mm）, and L（≧3mm）. The abovementioned classification system of the Japan esophageal association is a simple classification but is useful for the diagnosis of invasion depth.