examining the correlation between adenomatous colorectal polyps with different grade of dysplasia and their distribution in the large intestine, milad hospital, 2001-2004

background: the association between adenomatous polyps and malignancy has an important role in patient screening and follow up after polypectomy. due to less attraction towards the segmental resection, colonoscopic evaluation of malignancy has found its utmost importance role. polyp size and morphology have dictated the potential of malignancy in prior studies, however, in recent decade some authorities have paid further attention to dysplasia. during the present study, besides the aforementioned criteria, especial attention was paid to involved region of the colon. materials and methods: between june 2001 and march 2004, the distribution of 130 adenomatous polyps was compared with synchronous invasive or in situ cancer. patients were excluded from analysis if they had been previously familial adenomatous polyposis (fap) or inflammatory bowel disease (ibd). factors such as age, gender, location of the lesion, size of polyp, histological subtype of adenoma on biopsy, degree of dysplasia, synchronous cancer, color of polyp, and number of polyps were included in the data collection. results: multivariate logistic regression test was used to evaluate the association between malignancy and various clinical variables. it revealed histological subtype (or=16.4, 95%ci: 4.8-86.3), high grade of dysplasia (or=12.9, 95%ci: 4.5-37.9) and size .1cm (or=3.7, 95%ci: 1.9-14.1) to be independent predictor of malignancy. however, location of the lesion (or=5.9, 95%ci: 1.9-36.9) was an independent risk factor for high-grade dysplasia. conclusion: our study recommends to strict follow-up for 3 years intervalafter polypectomy for distal polyps to speleinc flexure, which are greater than 1 cm with villous component.