RESUMEN
BACKGROUND/AIMS: The precancerous lesion of colorectal cancer is adenoma. Adenoma with high grade dysplasia has been known as the lesion having high malignant potentials. The cancer with invasion to mucosa is limted to the mucosa, and it is difficult to pathologically differentiate the adenoma with high grade dysplasia. METHODS: Fifty three adenomas with high grade dysplasia (type I group) and 40 cancers with invasion to mucosa (type II group) for 4 years, were analyzed for the colonoscopic findings and pathological findings before and after EMR. RESULTS: Mean ages were 57.0 years old for type I group and 60.4 for type II group. Chief complaint for colonoscopy was rectal bleeding (21.0%) for type I group, and rectal bleeding (35.0%) for type II group. Mean sizes of the lesions were 1.18 cm for type I group, and 1.71 cm for type II group. Locations of the lesion were rectum 43.4%, sigmoid colon 32.1%, proximal colon 24.5% for type I group, and rectum 45.7%, sigmoid colon 42.9%, proximal colon 11.4% for type II group. Shapes of the lesions were Is 46.9%, Ip 30.6%, Isp 18.4%, LST 4.1% for type I group, and Isp 34.2%, Ip 31.6%, Is 18.4%, LST 5%, IIa depression 5%, Is+IIc 5% for type II group. Methods for therapy were EMR 60.4%, operation 1.9%, electrocoagulation 11.3%, observation 26.4% for type I group, and EMR 85.0%, operation 15.0% for type II group. Pathological agreement before and after EMR was 57.1% for type I group and 31.3% for type II group. CONCLUSIONS: Type II group had more rectal bleeding, larger, more Isp type, more EMR therapy, more pathological disagreement ratio before and after EMR, than type I group.