内視鏡で良性様所見を呈した生検陽性例の検討

THE POSITIVE CASES FOR CANCER BY GASTROFIBERSCOPIC BIOPSY IN LESIONS HAVING BENIGN APPEARANCE

Ⅰ．はじめに

　癌を疑いさえすれば今日ファイバースコープによる直視下生検あるいは直視下細胞診によってその確定診断を得ることはそれ程困難ではない¹⁾．しかし内視鏡的に癌を疑わなかった病変に癌がひそんでいることは，早期胃癌で少数ながら認められる内視鏡偽陰性例の経験や²⁾胃癌のretrospective studyの成績³⁾から想像することができる．そこで内視鏡で良性様にみえるものにどの程度癌がひそんでいるかということが問題となる．このことは誤診を防ぐために，また胃癌をより早期に発見するために是非解決しなければならない問題である．

　胃癌の早期診断の具体的な手順として著者らはレ線癌疑いや，内視鏡で少しでも悪性を疑わしめる所見のある場合に，従来は一般洗滌細胞診，2～3年来は直視下洗滌細胞診を原則として行ない，これらが陰性でなおかつ癌が疑わしい場合直視下生検を行なう方式をとってきた．ところが昨年11月著者らの開発による生検用ファイバースコープのカラーテレビが実用化し（第1図，第2図），生検手技の確実化と生検能率が大幅に向上したため最近は癌・非癌の鑑別診断だけでなく癌化の問題の研究資料となることを期待して明らかに良性と思われる限局性良性疾患にも積極的に直視下生検を行なっている，この様にして行なった生検症例を検討し，どの様な病型では胃癌を見落しやすいか，それらはどれ位あるか，誤診を除ぐためにはどうすればよいか，また従来良性として生検，細胞診を行なわなかった病変にどの程度癌がひそんでいるかなどについて，著者らが得た成績を報告する．

　As introduction of a biopsy method by means of color TV endoscopy gave rise to a positive attitude toward performing biopsy even in lesions already definitely confirmed as of benign nature by previous endoscopy, a study has been made in this paper as to how far cancer lesions might have been overlooked by endoscopic study alone, by correlating endoscopic diagnosis with that of biopsy. It also has been discussed regarding endoscopic and pathological characteristics of those cancerous lesions that have the possibility of being passed over as of benign nature, investigating all the cases hitherto operated on in the authors' clinic. The result is that even at present polypoid cancer lesion less than 1cm in diameter, and all those cancer lesions that look like benign ulcer, ulcer scar or erosion, if they are less than 3 cm in diameter, may possibly be overlooked. Not a few depressed lesions of similar size have been found to be already in the stage of advanced carcinoma. The best way to guard against such overlooking of malignancy is to perform biopsy as soon as any abnormal finding has been detected by endoscopy.

　These abnormal findings as confirmed by endoscopy have been shown here classified according to their respective types of early gastric cancer.

　The number of positive cases for cancer in this study was about one seventh of all the cases investigated. The possibility, that lesions confirmed as of benign nature by endoscopy may harbor cancer, is less than 1 per cent. Indiscriminate biopsy of benign lesions is therefore unnecessary except for some investigational purpose.