Ⅲ型早期胃癌の診断―内視鏡診断の立場

Diagnosis of Ⅲ Type Early Gastric Carcinoma: From Endoscopic Standpoint

　早期胃癌の肉眼分類によれば，陥凹型病変の代表的なものとしてはⅡcとⅢ型早期胃癌があげられており，Ⅲ型は理論的にはⅡcを伴わない潰瘍性早期癌である．しかし臨床的には，これと良性潰瘍との鑑別は困難であり，私どものところではⅢ型早期胃癌は診断されていない．

　従って私どもの症例で，かつてⅢ型のstageがあったと推定される悪性サイクルを示した陥凹型早期胃癌について，retrospectiveに検討し，果してⅢ型といえるstageがあったか，Ⅲ型の特徴的内視鏡所見があるか，Ⅲ型は内視鏡的に診断可能か等について検討した．

　No pure Ⅲ type early gastric carcinoma was found in a total of 216 lesions seen in 204 patients. Seventeen cases including 3 of advanced carcinoma diagnosed as benign gastric ulcer at the initial endoscopic examination were reviewed and 7 of those were again interpreted as benign gastric ulcer with or without certainty while the remaining ten cases were interpreted as carcinoma.

　Inadequate observation or poor photographing of a lesion resulted in misinterpretation in the seven cases again read as benign gastric ulcer in the reviewed study. Only two instances including a case of advanced carcinoma appeared type Ⅲ lesion on endoscopy after the detailed retrospective study.

　As a matter of fact, endoscopical differentiation of the type Ⅲ early gastric carcinoma from a benign gastric ulcer is extremely difficult in its active stage of ulceration.

　However, an endoscopic follow-up of such lesion may reveal Ⅱc appearing area surrounding the part of Ⅲ in the healing course, the entire lesion appearing as Ⅲ＋Ⅱc.

　It is concluded that endoscopic recognition of the type Ⅲ early gastric carcinoma will be possible when Ⅱc has appeared during a follow-up period.