THE PROBLEM OF DE-NOVO COLORECTAL-CARCINOMA

From April 1985 to March 1995, colonoscopy was carried out at our inst itution in 24 059 patients, 31 800 times in symptomatic and/or asympto matic average risk persons. 184 submucosal invasive carcinomas were de tected. Unlike protruding-type lesion, the depressed-type invades the submucosal layer, even though the size is within 10 mm. The depressed type of invasive carcinoma accounted for 20 lesions, and represented 1 0.9% (20 of 184) of all the invasive carcinomas. The pit pattern of de pressed-type lesions shows a small round pit (type III, pit pattern) a nd that of carcinoma lesions shows the irregular pit and non-structure (type V pit pattern).