胃底腺領域のⅡc型早期胃癌の内視鏡診断

Endoscopic Diagnosis of Type IIc Early Gastric Cancer Located in the Fundic Gland Mucosa

要旨　胃底腺領域内のⅡcを腺境界（F線）に接するもの（F-a群）と，完全に領域内にあるもの（F-b群）とに分けて検討した．F-a群11病巣，F-b群18病巣の計29病巣があり，これは全早期胃癌の8.2％，全Ⅱcの13.2％であった．年齢では差はほとんどみられなかったが，F-b群のみに女性が多かった．占居部位では胃体部および噴門部の後壁が圧倒的に多い．内視鏡的には皺襞集中が92％にみられ，F-a群は片側性，F-b群は全周性のものが多い．また病巣部の色調は白色調を示し，浸潤境界の不明瞭なものが多く，この3所見が胃底腺領域内Ⅱcの特徴と思われる．内視鏡診断は上記の3所見を見逃さないことと，大彎側の十分な伸展と確実な生検が基本である．この領域の微小Ⅱcは1病巣発見されているにすぎないが，この基本を守れば，更に多くのⅡcがより早期に発見されるだろう．

　Ⅱc type of early gastric cancer located in the fundic gland mucosa has been cnsidered to be very rare compared with the frequency for Ⅱc in the pyloric gland mucosa. In fact, in our Institute, only 29 lesions out of 220 lesions of Ⅱc (13.2%) have been detected endoscopically in the last 3 years (1984-1986). Therefore, histopathological and endoscopic findings concerning them were studied in this report.

　Twenty nine lesions of Ⅱc were histologically classified into two groups; in one group, Ⅱc was located partially in contact with a boundary line (F-line) between the fundic gland mucosa and the pyloric gland mucosa as F-a group. In another group, Ilc was located completely in the fundic gland mucosa as F-b group.

　A difference in age between the two groups was not significant, but, in sex, F-b group was relatively dominant in the female. Localization of these Ⅱc lesions in the stomach was markedly distributed on the posterior wall of the corpus and cardia in both groups.

　In endoscopic features of the lesions, converging folds of the gastric mucosa were dominantly recognized in 92% of both groups. Partial converging folds were recognized in the lesions of F-a group and severe converging folds were seen around all the lesion in F-b group. A border showing the extent of the invasion of the carcinoma was unclear in 68% of the lesions. White colored mucosal depression was observed in 44% of the lesions. Especially in the cases with undifferentiated carcinoma, white discoloration of the lesion was observed in 68.8%. In the cases with differentiated carcinoma, red colored mucosal discoloration of the lesion was observed in 77.8% of the lesions

　Therefore, when the endoscope detects a depressed lesion located on the posterior wall of the corpus and cardia, probability that the lesion is malignant must be admitted.