 Endoscopic mucosal resection EMR is considered to be a gold standard of therapy of colorectal lateral spreading tumors LST without significant risk for lymphatic spread. According to the investigators previous study, local residual neoplasia LRN after conventional endoscopic mucosal resection EMRoccurs in up to 21 of cases. Endoscopic therapy of LRN was not sufficient in 53 and has not been standardized yet. 