AIM:To investigate the relationship between post-endoscopic resection(ER) scars on magnifying endoscopy(ME) and the pathological diagnosis in order to validate the clinical significance of ME.METHODS:From January,2007 to June,2008,124 patients with 129 post-ER scar lesions were enrolled.Mucosal pit patterns on ME were compared with conventional endoscopy(CE) findings and histological results obtained from targeted biopsies.RESULTS:CE fi ndings showed nodular scars(53/129),erythematous scars(85/129),and ulcerative scars(4/129).The post-ER scars were classified into four pit patterns of sulci and ridges on ME:47 round;54 short rod or tubular;19 branched or gyrus-like;and9 destroyed pits.Sensitivity and specificity were 88.9% and 62.5%,respectively,by the presence of nodularity on CE.Erythematous lesions were high sensitivity(100%),but specificity was as low as 36.7%.The range of the positive predictive value (PPV) on CE was as low as 10.6%-25%.Nine type  pit patterns were diagnosed as tumor lesions,and 120 cases of type pit patterns revealed non-neoplastic lesions.Thus,the sensitivity,specificity,and the PPV of ME were 100%.CONCLUSION:ME findings can detect the presence of tumor in post-ER scar lesions,and make evident the biopsy target site in short-term follow-up.Further large-scale and long-term studies are needed to determine whether ME can replace endoscopic biopsy. AIM: To investigate the relationship between post-endoscopic resection (ER) scars on magnifying endoscopy (ME) and the pathological diagnosis in order to validate the clinical significance of ME. METHODS: From January, 2007 to June, 2008, 124 patients with 129 post-ER scar lesions were enrolled. Mucosal pit patterns on ME were compared with conventional endoscopy (CE) findings and histological results obtained from targeted biopsies .RESULTS: CE fi ndings showed nodular scars (53/129), erythematous scars (85/129 ), and ulcerative scars (4/129). The post-ER scars were classified into four pit patterns of sulci and ridges on ME: 47 rounds; 54 short rods or tubular; 19 branched or gyrus-like; and 9 destroyed pits. Sensitivity and specificity were 88.9% and 62.5%, respectively, by the presence of nodularity on CE. Erythematous lesions were high sensitivity (100%), but specificity was as low as 36.7%. The range of the positive predictive value (PPV) on CE was as low as 10.6% -25% .Nine type  pit patterns were diagnosed as tumor lesions, and 120 cases of type pit patterns revealed non-neoplastic lesions. Thus, the sensitivity, specificity, and the PPV of ME were 100% .CONCLUSION: ME findings can detect the presence of tumor in post-ER scar lesions, and make evident the biopsy target site in short-term follow-up. Fusion large-scale and long-term studies are needed to determine whether ME can replace endoscopic biopsy.