陥凹型早期胃癌の問題点―内視鏡的問題点

Problems Involving Early Gastric Cacer of Depressed Type

　筆者が昭和34年末に胃カメラ検査を行なうようになってから最近までの10年間に，術前に胃内視鏡検査を行ない，病変が内視鏡フィルムに撮影されている早期胃癌症例は101例，113病変である（表1，本稿では重複病変にはふれない）．この間の内視鏡診断を振り返ってみると，内視鏡器具，検査方法の進歩にともなって，診断能も向上の一途を辿ったのではあるが，とくに直視下胃生検が術前診断の揚に登場してきてからは，良きにつけ悪しきにつけ内視鏡診断についての考え方ないしは評価に大いなる影響を及ぼし，内視鏡診断の意味づけ，根拠をより明らかにしなければならなくなったのである．他方，早期胃癌症例数の増加により早期胃癌に関する臨床的ないしは臨床病理学的知識が一層普遍化したことと，早期胃癌症例についての経時的推移が明らかにされてきたことなどから，診断内容の面においても大いなる進歩と変遷があったことも周知の通りである．

　本稿においては陥凹型早期胃癌について前述した2つの観点から診断内容の変遷と内視鏡診断の問題点を指摘してみたい．

　To elucidate some problms in endoscopic diagnosis of depressed type early gastric cancer, we have selected 101 cases of well photographed gastric lesions out of all cases of early gastric cancer encountered during the past ten years.

　1. Of 101 cases, depressed type early gastric cancer amounted to 73 (72 per cent). The accuracy rate of endoscopic diagnosis was 67 per cent.

　2. According as gastric biopsy has come to be employed for preoperative diagnosis of cancer, more exactness is inevitaly being required in endoscopic diagnosis. Such a tentative diagnosis as “suspicion of early gastric cancer” should not be used too easily. At. least, it is justified only as a temporary diagnosis to be made in the process of thorough examination. Otherwise it should be placed in a final category of “non-determined case” endoscopically considered. This attitude must be maintained thoughout in reducing the numbers of false positive cases as well as those in which endoscopic diagnosis has gone too far. Including cases resected owing to erroneous diagnosis, the accuracy rate in our cases were for the first four years 40 per cent and in the latter six, 54 per cent.

　3. Gastric biopsy and diagnosis of depressed type early gastric cancer

　There are still some cases in which diopsy was not done because cancer was taken for granted by endoscopy alone and some others where biopsy done without because the examiner was confident of his diagnosis in benign lesion.

　Gastric biopsy is now so capable of exact diagnosis in many cases that after all the most important problem is to determine whether it is in order as judged from endoscopic findings. In other words, the question boils down to this: By selecting cases in which endoscopic findings cast no doubt about the malignancy of the lesion and other cases in which the benignity of the lesion is beyond any doubt, one should analyze infinitesimal findings that are falsely similar to endoscopic conviction. At least for the time being, vigorous biopsy at every opportunity paves the way to the solution of this problem. It is emphasized that the nature of depression surface, especially its flashy coarseness, irregular reddening and discoloration are findings of utmost Importance.

　4. Malignant cycle in depressed type early cancer and its depth invasion

　Energetical follow-up of benign ulcer careful observation of phenomena of malignant cycle may lead to the recognition of early phase of its canceration. It may also prove the first step to the dignosis of type Ⅲ early gastric cancer which is very hard to diagnose at present.

　Assumption of depth invasion in each variety of early gastric cancer is still a hard task. In depressed type, its aggregate of infiltration, mucosal or submucosal, can accurately be diagnosed by correct interpretation of diffuse protrusions around depressed area.

　Reference is made not only to both endoscopical and biopsical diagnoses in early stage of scirrhus cancer, but also to the possibility that afore-mention ed diffuse protrusions around depression be utilized as a criterion to the diagnosis.