食道粘膜癌の内視鏡診断と病型分類の問題点

The Problem of Endoscopic Diagnosis and Classification of Mucosal Esophageal Cancer

要旨　食道粘膜癌（m癌）はリンパ節転移がほとんどなく，予後も良好であることから早期癌と呼ぶべき性質を備えている．m癌の内視鏡型はⅡ型が中心ではあるが，現行の病型分類ではⅡa型，Ⅱc型にm癌，sm癌が広く含まれるためにm癌が見えてこないのが問題である．このため当科の表在食道癌86病巣を見直して，m癌の病型について検討した．この結果，m癌の病型はⅡb型および，Ⅱc型のうち陥凹面内が平滑で，わずかな微細顆粒が少数見られるもの，Ⅱa型は明らかに粘膜面に露出した丈の低い隆起とすると，m癌を抽出することができる．更に，残ったsm癌の扱いについて検討した．

　As mucosal esophageal cancer has almost no lymph node metastasis and has a pretty good prognosis, we would like to call only these lesions“early esophageal cancer”. Endoscopically, m cancer is usually revealed as type Ⅱ lesion, but, in today's classification, it can not be distinguished whether Ⅱa and Ⅱc lesions are m or sm cancer. Because of this, 86 superficial esophageal cancer lesions were reexamined. As a result, it was found that all Ⅱb type lesions, Ⅱc lesions with a smooth or particularly fine granular surface and Ⅱa lesions with a sharp tumor edge were located only in the mucosa. However Ⅱc lesions with a granular, nodular or roughly irregular surface and Ⅱa lesions with epithelial overlapping of the tumor demonstrated sm cancer. The features of sm cancer are discussed here again.