食道扁平上皮癌の拡大内視鏡診断—JES Type B2のバリエーションとその解釈

Diagnosis of Esophageal Squamous Cell Carcinoma by Magnifying Endoscopy:Variations of JES Type B2 and Their Interpretation

要旨●食道扁平上皮癌のJES Type B2を“非ループ状の血管を3本以上認めた領域”と定義するとJES Type B2の頻度は32.9％で，正診率は72.4％であった．JES Type B2がT1a-MM/T1b-SM1の指標とすると，PPVは24.0％と低かった．JES Type B2をB2-AVA，B2-Inflammation，B2-Narrow，B2-Broadと亜分類すると，B2-BroadのみがT1a-MM以深の指標として有用で，この場合の正診率は91.4％，PPVは70.6％まで改善した．JES Type B2にはバリエーションが存在し，AVAを構成する血管（B2-AVA）や炎症を示唆する血管（B2-Inflammation）は深達度診断に寄与せず，それ以外のJES Type B2（B2-Narrow/B2-Broad）は領域の大きさが癌深達度に関連している可能性が示唆された．

　The frequency of JES Type B2 esophageal squamous cell carcinoma and the accuracy of its diagnosis were 30.2% and 72.3%, respectively, when this carcinoma was defined as "an area with at least three non-looped blood vessels". When JES Type B2 was used as a predictor of T1a-MM/T1b-SM1, PPV（positive predictive value）was low（24.0%）. When JES Type B2 was subdivided into B2-AVA, B2-Inflammation, B2-Narrow, and B2-Broad, only B2-Broad was a useful predictor of T1a-MM and deep lesions with improved accuracy（91.4%）and PPV（70.6%）. These results suggest that there are variations of JES Type B2. Of these, blood vessels constituting AVA（B2-AVA）and those suggestive of inflammation（B2-Inflammation）do not contribute to diagnosis of invasion depth. However, for other variations of JES Type B2（B2-Narrow/B2-Broad）, the size of the area may be related to the invasion depth of the cancer.