Abstract: ObjectiveTo evaluate the clinical value of magnifying endoscopy in diagnosis and treatment of colorectal benign neoplastic lesions.Methods78 colorectal lesions in 61 patients were examined with magnifying colonoscopy after indigo carmine dye, and a pit pattern diagnosis was made for every lesion according to Kudo's classification.All the lesions were totally resected, and the specimen were sent for pathologic examinations.ResultsThe diagnostic sensitivity of neoplastic lesions was 98.4% and specificity was 85.7% when types Ⅰ and Ⅱ represented the pit pattern of nonneoplastic lesions, whereas types Ⅲ, Ⅳ, and Ⅴ represented adenoma and early colorectal cancer. The overall accuracy in differentiating adenoma and early colorectal cancer from nonneoplastic lesions was 96.2%.94.5% of adenomarous lesions were treated by colonoscopy.ConclusionThe magnifying colonoscopy can provide an instantenous accurate diagnosis of tumorous lesions in colon and rectum. Synchronize, minimally invasive and curative treatment is possible to be completed by using it for a large number of lesions.

Key words: magnifying colonoscopy, colorectal neoplasm, diagnosis, treatment, pit pattern, pathology