6958 Daignosis of submucosal carcinomatous infiltration by microscanner in early colorectal cancer.

Abstract

AIM: To evaluate the efficacy of the microscanner (MS) in diagnosing the depth of submucosal invasion in early colorectal cancer. PATIENTS: One hundred seventy-four patients with colorectal cancers including 80 protruding lesions (mucosal cancer (m) 41, submucosal cancer (sm) 39) and 94 superficial lesions (m, 41; sm, 52). METHODS: The diagnostic accuracy of depth of invasion in early colorectal cancer by MS was analyzed. The MS diagnosis was made based on the extent of a tumor echo into the third hyperechoic layer of the bowel wall which is considered to be the submucosa. Carcinomas which showed involvement of the submucosal layer were divided into two groups according to the histological degree of invasion: sm1, a group in which the depth of invasion was 1/3 of the submucosal layer or less; sm2-3, a group in which the depth of invasion of the submucosa was over 1/3. The MS diagnosis was compared with the histological diagnosis of the depth of invasion in each lesion. RESULTS: 1) Visualization of the lesion by MS was possible in 87% (152/174) of the lesions, i.e., 81% in protruding lesions and 92% in superficial lesions. 2) The accuracy of MS in diagnosing the depth of invasion in all lesions, in protruding lesions, and in superficial lesions was 93%, 88%, and 95%, respectively. 3) Diagnostic accuracy of MS as to the degree of submucosal invasion was 91% in m and sm1 cancer and 96% in sm2-3 cancer. CONCLUSIONS: MS is useful for the diagnosis of the depth of invasion in early colorectal cancers. Improvement of the accuracy in diagnosing protruding lesions is required.