食道表在癌の深達度診断を誤った要因―病理の立場からの検討

Superficial Esophageal Carcinomas, the Estimation of Whose Depth is Complicated

要旨　深達度が粘膜下層までにとどまる食道表在癌においては，治療前の内視鏡的深達度診断がEMR適応の有無を決定する重要な因子となるため，肉眼型に応じた深達度診断が報告されている．1990年代は，症例の蓄積も十分とは言いがたく，現在に比べれば内視鏡の技術・画像が不十分であったために，微小な表面性状の変化をとらえることができずに，内視鏡的深達度診断は，概して“浅読み”傾向にあった．最近は，症例経験の蓄積と内視鏡技術の進歩により，より細かな食道表在癌の表面性状が読み取れるようになったが，微小な表面性状の変化をもって，深部浸潤と判断してしまう“深読み”の内視鏡的深達度診断もみられる．

　Endoscopic estimation of tumor depth of superficial esophageal carcinoma is important for deciding therapeutic strategy, such as endoscopic mucosal resection (EMR). Recent studies have reported a correlation between endoscopic findings and tumor depth of superficial esophageal carcinoma. In the 1990's, because accumulation of knowledge concerning superficial esophageal carcinoma cases was insufficient and the technology of endoscopy had not developed as extensively as it now has, the tumor depth of superficial esophageal carcinomas was sometimes underestimated by endoscopy. On the other hand, recent advances in endoscopical observation have resulted in the discernment of minute mucosal findings concerning esophageal carcinoma that can be detected endoscopically. However, in cases of superficial esophageal carcinomas, the tumor depth has sometimes been endoscopically overestimated. Mucosal findings of superficial esophageal carcinomas, such as erosion and hemorrhage, can result in endoscopical overestimation of tumor depth.

　1) Departments of Pathology and Surgery, Tokai University School of Medicine, Isehara, Japan