胃底腺領域の陥凹型早期癌に関する病理組織学的検索―分化型癌と未分化型癌の比較

Histopathological Study on Early Gastric Carcinoma of Depressed Type in the Fundic Gland Area: Comparison between differentiated type and undifferentiated type

要旨　腸上皮化生の有無に関係なく胃底腺粘膜で囲まれた陥凹型早期癌を解剖学的胃底腺領域陥凹型早期癌と仮に規定し，これに合致する58症例62病変について，病理組織学的立場から検討した．組織学的に分化型癌29病変と未分化型癌33病変に分類された．前者は男性に多く，膨張型発育を示し，腸上皮化生を伴うことが多いなどの特徴を示した．後者は女性に多く，49歳以下はすべてそうであり，分化型癌より大きく，小さい病巣でも深部浸潤の傾向があり，潰瘍合併率がより高く，浸潤型発育を示し，腸上皮化生は欠くか軽度で，癌に伴う粘膜下層の線維化は強く，粘膜内癌巣にも線維化をみることがあるなどの特徴がみられた．以上の特徴の指摘と共に“linitis plastica”の初期病変について簡単に考察を加えた．

　Histopathological study on depressed type early gastric carcinoma in the anatomical fundic gland area with or without intestinal metaplasia was done in 62 lesions of 58 resected specimens obtained from 58 patients. The results were as follows.

　1) The 62 lesions were histopathologically classified as differentiated (29) and undifferentiated types (33), according to Nakamura. The average age was 59 years for the differentiated type and 54 for the undifferentiated type, and the male to female ratio, twenty-two to five and thirteen to eighteen, respectively. While the undifferentiated type was found in 78% of the females and 38% of the males, the differentiated type was found in 22% and 62%, respectively. Among the patients 49 years old or younger differentiated type was recognized only in the males.

　2) The largest diameter was, on average, 24 mm for the differentiated type and 32 mm for the undifferentiated type. Submucosal invasion was found in 41% of the differentiated type and 55% of the undifferentiated type, and in the latter, it was found even when the cancer being smaller than 10 mm in diameter.

　3) Peptic ulcer accompanied the carcinoma in 72% of the differentiated type and in 91% of the undifferentiated type. Almost all the ulcers were superficial, Ul-Ⅱ or healed. The carcinoma with clear borders was seen in 79% of the differentiated type and 91% of the undifferentiated type. Seventy-two percent of the differentiated type showed expansive growth pattern and 88% of the undifferentiated type revealed infiltrative growth pattern.

　4) While intestinal metaplasia in the fundic gland mucosa surrounding the carcinoma was moderate to severe in the differentiated type, it was and nil to slight in the undifferentiated type, The severity of mucosal atrophy was comparable to that of intestinal metaplasia. Interestingly, there was a case of differentiated type with no intestinal metaplasia around the carcinomatous focus.

　5) Submucosal fibrosis associated with carcinomatous invasion was more severe in the undifferentiated type. The frequency and the extent of lymphatic permeation were about the same in both types.

　6) The mucosal fibrosis in the carcinomatous focus was found in only 4 lesions, all of which revealed marked submucosal fibrosis as well.

　Based on these results it is said that the clinicopathological characteristics are distinctive between differentiated and undifferentiated types of early gastric carcinoma. A brief discussion was made on the initial lesion of the “linitis plastica”-type carcinoma.