前癌病変としての胃線状潰瘍の位置

Position of Linear Ulcer of the Stomach as a Precancerous Lesion

　1926年，Hauserが病理組織学的な立場から胃潰瘍から胃癌が発生すると説き，いわゆる“潰瘍癌”の病理組織学的規準を提唱して以来¹⁾，わが国においても，Hauser説が多くの病理学者に支持されてきた^2)3)4)6)7)．しかし一方では，Stromeyer¹⁰⁾やKonjetzny¹²⁾のように，潰瘍からの癌化は非常にまれであり¹¹⁾，潰瘍の周辺の慢性胃炎から癌が発生するという説や，最近では粘膜内癌がかなりの期間存在していて，その間に潰瘍が2次的に形成されるという説が内科医の胃潰瘍の経過観察から支持されてきた⁸⁾³⁴⁾．

　しかし，切除胃組織標本から得られる断面的な所見のみからでは，癌または潰瘍先行のいかんを決定することはむずかしく，決定的な確証は得られない．この問題を解決するには，慢性胃潰瘍を臨床的に長期間にわたって正確に胃直視下生検を基礎にして経過観察し³⁵⁾，慢性胃潰瘍からの癌化の頻度を統計的に処理するか，典型的な慢性胃潰瘍の辺縁に微小粘膜内癌を見いだし，これが偶然の発生ではないことを確認するしかない．

　Of 190 cases of early gastric cancer encountered in our department from 1961 through 1972, 21 belonged to ulcer-cancer that fulfilled Hauser's pathologic criteria. Mucosal cancer accompanying linear ulcer over 30 mm in length was further found in 5 cases (2.6 per cent). This figure corresponded to 23.8 per cent of ulcer-cancer that met Hauser's criteria. Centering around these 5 cases, we have made a comprehensive study of histologic and clinical findings of linear ulcer. Included in this study is also a case of early gastric cancer in which most of cancer nests on the margins of linear ulcer showed depth degree of only m, with a part of them deep into sm. In addition, 2 cases of sub-early cancer were studied where only a small part of it had pm degree of depth invasion. As a result, we have found that, as described below, linear ulcer of the stomach accompanied with cancer on its margins differs little from benign ulcer, not only in the mother ground of development but also in its histologic and clinical findings.

　1. The distance between ulcer and the pyloric ring is in inverse proportion to the length of linear sulci.

　2. Deformity of the stomach as seen in x-ray also shows that length of linear sulci is proportionate to the degree of contraction of the lesser curvature and that the distance between ulcer and the pyloric ring is inversely proportional to the degree of lesser curvature contraction.

　3. Malignant linear ulcer is located in the border area either between fundic and pyloric gland area or between pyloric and duodenal gland area. This tendency is the same as in benign linear ulcer.

　4. Age distribution of malignant linear ulcer is more inclined to the predilection age of gastric ulcer than to that of early gastric cancer.

　5. As in benign gastric ulcer, the length of period of patient's suffering and the length of linear sulci show a high correlation.

　6. Gastric analysis by tetragastrin or histamine method shows in malignant ulcer predominantly hyperchlorhydria, fairly akin to that of benign ulcer.

　The above data suggest that linear ulcer accompanied with cancer is originally of benign nature. Consequently. the majority of cancer lesion on the margins of linear ulcer is to be regarded as cancer developed on its margins.

　During the same period the total number of gastric ulcer examined by endoscopy amounted to 1291 cases. Of these, relatively long linear ulcer was seen in 113 cases (8.8 per cent). Coexistent cancer in all ulcer cases and in linear ulcer cases among them was seen in 1.7 per cent and 4.4 per cent, respectively. In a series of gastric mass screening, cancer was seen in 5 cases (2.9 per cent) out of 171 cases that had endoscopically atrophic gastritis without ulcer scar. Its χ² test with the rate of cancer coexistent with linear ulcer, however, revealed unexpectedly no great difference.