Abstract
Since January 1982, 275 early colonic carcinomas undergoing total endoscopic resection were studied. Of this series, 234 lesions showed some adenoma components, whereas the remaining 41 lesions lacked adenoma components. Minute carcinomas measuring ≤ 5 mm (21 lesions) were most commonly the hemispheric protruding type lesions (IIs, 9 lesions), followed by superficial protruding type lesions with a height of ≤ 3 mm (IIa, 6 lesions). There also were 2 superficial depressed-type lesions that were slightly concave. Eight of these minute carcinomas may have developed by de novo carcinogenesis, and 2 had already invaded the submucosa. Therefore every effort should be made not to overlook lesions measuring ≤ 5 mm in diameter. That none of these lesions were located in the rectum indicates the acute necessity for improved examination procedures. With regard to IIa lesions measuring > 5 mm, 92.3% were discovered by videoendoscopy. This high detection rate was attributed to the growing use of videoendoscope systems and reflects heightened interest on the part of endoscopists in superficial type lesions.