早期胃癌治療のための精密検査―深達度を読む

Evaluation of Invasivity of Early Gastric Cancer by Radiologic, Endoscopic and Ultrasonographic (EUS) Examination

要旨　内視鏡的治療を念頭において，mかsm以深かに絞って，深達度診断能を検討し，以下の結論を得た．（1）隆起型早期胃癌においてX線では隆起頂上の陥凹が，内視鏡では隆起頂上の陥凹および白苔付着と健常粘膜に覆われた粘膜下腫瘍様の立ち上がりがsm以深浸潤の重要な指標であった．EUSでは第3層の画然とした断裂が指標となったが，粘膜筋板が挙上するものではsm浸潤の診断が困難であった．（2）Ul(－)陥凹型早期胃癌においてX線では強い透亮像に囲まれた深い陥凹が，内視鏡では健常粘膜に覆われた周園隆起と白苔を有する陥凹がsm以深浸潤の指標であった．EUSでは第3層の画然とした断裂がsm浸潤の指標となった．（3）Ul(＋)陥凹型早期胃癌においてX線では粘膜ひだ先端の太まり・癒合，周囲透亮，辺縁の画然とした硬化像が，内視鏡では粘膜ひだ先端の太まり・癒合，周囲隆起，台状挙上，陥凹面の硬化像がsm以深浸潤の指標となった．EUSでは胃内外への壁肥厚がsm浸潤の指標であった．しかし，開放性潰瘍合併例においてはいずれの検査法においても診断が困難であった．

　To evaluate diagnostic findings of invasivity of early gastric cancer invading further than the submucosal layer, we studied two hundred and twenty cases of early gastric cancer. Our results were as follows:

　1) In the elevated type early gastric cancer, deep depression on the surface of a tumor indicated submucosal invasion, but the size of a lesion did not correlate with invasivity by radiologic examination. Both ulceration on the surface and a submucosal tumor-like mucosal elevation covered with normal mucosa were important findings by endoscopic examination. The destruction of the third layer suggested submucosal infiltration of tumor cells by EUS.

　2) In the depressed type early gastric cancer without ulceration or ulcer scar, radiolucency around a deeply depressed lesion indicated the submucosal invasion by radiologic examination. A surrounding normal mucosal elevation and a white coated depression on endoscopic examination suggested the submucosal invasion. The destruction of the third layer showed the submucosal infiltration by EUS.

　3) In the depressed type early gastric cancer with ulceration or ulcer scar, elevated and fused mucosal folds at the rim of a depression, radiolucency around a depression, and distinct wall rigidity were useful for evaluating invasivity by radiologic examination. Swelling and fusion of the mucosal folds at the rim of a depression, elevation around a depression, plate-like elevation, and rigidity of an entire depressed lesion were important findings suggesting submucosal invasion by endoscopic examination. Both intra- and extraluminal thickening of the gastric wall indicated submucosal infiltration by EUS.