linitis plastica型胃癌，特にその初期病変の診断―X線診断を中心に

Early-stage Linitis Plastica Type Gastric Cancer for the Purpose of Radiological Detection

要旨　linitis plastica型胃癌の診断能を向上させる目的で胃体部と胃底部に発生した未分化型癌のX線所見を検討した．早期癌68病変（M癌39病変，SM癌29病変）の肉眼型はすべて陥凹主体の病変であった．その中で潰瘍や皺襞集中を伴う病変は37病変（54％）であった．陥凹面の性状は大小顆粒状模様が55病変，胃小区模様が消失した平滑模様が7病変，胃小区類似（Ⅱb類似）の模様が6病変であった．胃小区模様が消失した平滑模様7病変中5病変はSM癌であり，胃小区類似の模様の病変はすべてM癌であった．また，陥凹周囲に透亮像を伴う15病変はすべてSM癌であった．4型進行胃癌26病変の中で原発巣に皺襞集中がない病変は19病変（73％）であった．また，原発巣が胃体部の皺襞の中に存在するものは12病変（46％）であった．胃体部の皺襞に存在し皺襞集中がない早期胃癌の発見が重要と考えられ，それらのX線像は皺襞を横断する溝状陰影，皺襞の中断，皺襞の中断を伴うバリウム陰影，皺襞間のバリウム陰影であった．4型進行胃癌の中で胃の全体的な収縮が生じていない潜在的linitis plastica型胃癌6病変のX線所見は，胃角もしくはHis角の変形が3病変，辺縁の硬化像が2病変，皺襞の肥大が2病変，皺襞間の狭小化が2病変，皺襞表面の顆粒像が4病変，胃小区の不規則な強調像が5病変であった（重複あり）．潜在的なLP型胃癌の診断は伸展不良の所見が不明瞭であるため，粘膜ひだや粘膜模様の微細な変化を表すX線検査が必要である．

　We studied the X-ray findings of undifferentiated type gastric carcinoma arising in gastric body and fundus to improve the ability to diagnose linitis plastica-type gastric carcinoma. All of 68 early gastric cancers were macroscopically depressed type and 37 lesions (54％) had ulcers or ulcer scars with fold convergence. Meanwhile among 26 lesions of type 4 advanced gastric cancers only 7 lesions (27％) had ulcers or ulcer scars with fold convergence and 12 lesions (46％) were located in the area of gastric fold. Therefore, detection of early cancer located in the area of gastric fold without fold convergence is important. These lesions were demonstrated by X-ray studies as furrowed shadow crossing the fold, interruption of the fold, or barium shadow between the folds. An undifferentiated type gastric carcinoma arising in gastric body may have an extensive infiltration in the gastric wall. Therefore, careful investigation of not only of the mucosal lesion but also the surrounded area are necessary. To detect the latent linitis plastica-type gastric carcinoma, it is important to take notice of the changes of mucosal folds and of the mucosal fine structures.