[Study on mucosal carcinomas of the large intestine, polypectomized for the recent 5 years]

Intramucosal carcinomas of the large intestine, polypectomized from 1988 to 1992 were investigated. Out of 111 lesions of intramucosal carcinoma, 106 cases (95.5%) co-existed with adenoma. The incidence of co-existence with adenoma was 0%, 14.4%, 31.5%, 26.1%, 18.9% and 9.0% in the lesions within 4mm, 5-9mm, 10-14mm, 15-19mm, 20-29mm, and over 30mm in diameter, respectively. The incidence of gross findings in the co-existed cases of cancer and adenoma was 0.9%, 15.1%, 32.1%, and 51.9% for IIa, Is, Isp, and Ip types, respectively. Histological incidence of co-existed adenomas was 63.2%, 31.1% and 5.7% for tubular, tubulovillous and villous types. Occupation rate of cancer tissue was within half in the majority of co-existed lesions.