The frequency of histopathologic findings in flat and depressed colorectal lesions in patients referring to Taleghani hospital in 2006

Non-polypoid colorectal neoplasms and related malignancies are difficult to be detected using traditional colonoscopy. In this study, we attempted to evaluate frequency of flat and depressed colorectal neoplasms using high-magnifying colonoscopy. Patients with medical indication of colonoscopy who referred to Talaghani hospital in 1385 were evaluated. After preparation, total colonoscopy (Olympus, CF-Q240TL, Japan) was performed up to cecum. Lesions were classified according to macroscopic presentation and Paris classification, and then they were evaluated regarding pit patterns after 100-fold magnification. Pathologic findings of lesions were studied by two expert pathologists. One hundred patients with mean age of 44.3 ± 16.1 were studied. In total 27 lesions (17 polypoid, 10 non-polypoid) were found in 18 patients. Peduculated polyps (9 polyps) were the most common lesions. We found 8 flat and 2 slightly elevated polyps. There was no depressed lesion. In pathologic examination, there were 21(77.8%) adenomas, mostly tubular (12, 66.6%). One adenocarcinoma was also detected. Pit pattern II was the most common pattern found. As non-polypoid neoplasms are frequent lesions in Iran, we recommend performing high-magnifying colonoscopy in patients with suspected presentations in traditional colonoscopy.