AIM:To evaluate the feasibility and the outcome of endoscopic mucosal resection(EMR)for large colorectal tumors exceeding 4 cm(LCRT)undergoing piecemeal resection. METHODS:From January 2005 to April 2008,146 digestive tumors larger than 2 cm were removed with the EMR technique in our department.Of these,34 tumors were larger than 4 cm and piecemeal resection was carried out on 26 colorectal tumors.The mean age of the patients was 71 years.The mean follow-up duration was 12 mo. RESULTS:LCRTs were located in the rectum,left colon,transverse colon and right colon in 58%,15%, 4%and 23%of cases,respectively.All were sessile tumors larger than 4 cm with a mean size of 4.9 cm (4-10 cm).According to the Paris classification,34%of the tumors were typeⅠs,58%typeⅡa,4%typeⅡb and 4%typeⅡc.Pathological examination showed tubulous adenoma in 31%,tubulo-villous adenoma in 27%,villous adenoma in 42%,high-grade dysplasia in38%,in situ carcinoma in 19%of the cases and mucosal carcinoma(m2)in 8%of the cases.The two cases(7.7%)of procedural bleeding that occurred were managed endoscopically and one small perforation was treated with clips.During follow-up,recurrence of the tumor occurred in three patients(12%),three of whom received endoscopic treatment. CONCLUSION:EMR for tumors larger than 4 cm is a safe and effective procedure that could compete with endoscopic submucosal dissection,despite providing incomplete histological assessment. AIM: To evaluate the feasibility and the outcome of endoscopic mucosal resection (EMR) for large colorectal tumors exceed 4 cm (LCRT) undergoing piecemeal resection. METHODS: From January 2005 to April 2008, 146 digestive tumors larger than 2 cm were removed with the EMR technique in our department. Of these 34 tumors were larger than 4 cm and piecemeal resection was carried out on 26 colorectal tumors. The mean age of the patients was 71 years. The mean follow-up duration was 12 months. RESULTS: LCRTs were located in the rectum, left colon, transverse colon and right colon in 58%, 15%, 4% and 23% of cases, respectively. All were sessile tumors larger than 4 cm with a mean size of 4.9 cm (4-10 cm). According to the Paris classification, 34% of the tumors were type I s, 58% type IIa, 4% type IIb and 4% type IIc. Pathological examination showed tubulous adenoma in 31%, tubulo-villous adenoma in 27%, villous adenoma in 42 %, high-grade dysplasia in 38%, in situ carcinoma in 19% of the cases and mucosal carcinoma (m2) in 8% of the cases. two cases (7.7%) of procedural bleeding that occurred were managed endoscopically and one small perforation was treated with clips. After follow-up, recurrence of the tumor occurred in three patients (12%), three of whom received endoscopic CONCLUSION: EMR for tumors larger than 4 cm is a safe and effective procedure that could compete with endoscopic submucosal dissection, yet providing incompletehistological assessment.