RESUMO
UNLABELLED: INTRODUCTION, STUDY AIM: Colorectal carcinoma is one of the most frequent malignancies. Most frequently, neoplasms, including malignant precursors, are in the form of polyps, although these might be of a non-tumour origin. The aim of this prospective multicentre study was to provide an overview of coloscopic identification and biological nature of polyps. RESULTS: 3,400 consecutive coloscopies performed between 2009 and 2010 were analyzed. At different centres, the top of the cecum was reached in 89% to 93% and terminal ileum in 73% to 87% of cases. In the above 40 age group, 26.6% were screening coloscopies. The mean age of the above 40 patients was 56 years. The incidence of potential neoplastic lesions (polyps, carcinomas), advanced adenomas and carcinomas were: 7.8 %, 0.8 % and 0.16 %, respectively, in the above 40 age group, 41.5 %, 9.8 % and 1.6 %, respectively, in the 40-50 years age group and 70.5 %, 31.3 % and 6.8 %, respectively, in the above 50 age group. The incidence of tubular adenoma and hyperplastic polyps was 23.9% and 66.2%, respectively, in the below 40 age group and 53.1% and 26.1% in the above 50 age group. 57.8% of advances neoplasms were located in the rectosigmoid a descendent colon. The incidence ratio for adenomas and hyperplastic polyps was 76.6% and 14%, respectively, for rectosigmoid colon, 63.6 and 17.4 %, respectively, for descendent colon, 63.6 and 11.4 % for traverse colon and 63,4 a 17,9 %, respectively, for cecum and ascendant colon. The incidence of tubulovillous adenomas and hyperplastic polyps in pedunculated polyps larger than 1 cm was 19.4 % and 20.4 %, respectively, and 34.2 % and 13.1 %, respectively, in other polyps. The incidence of potential lesions (polyps and carcinomas), advanced adenomas, carcinomas and advanced neoplasms was 66.7 %, 23.1 %, 5.8 % and 28.9 %, respectively, in women and 63.1 %, 30.0 %, 5.7 % and 34.7 %, respectively, in men. CONCLUSION: The top of the cecum was reached in a higher proportion of cases than required, although this was lower than in the majority of other recent studies. Terminal ileum was reached in high number of cases. The incidence of polyps and neoplasms rose sharply from 40 years of age. Therefore, the screening threshold should be extended to the below 50 age group. Hyperplastic polyps predominated in younger age and adenomas in the above 40 age group. Histological profile was similar and did not suggest importantly different pathogenesis with respect to localization. There were relatively fewer adenomas and more hyperplastic polyps in pedunculated polyps and vice verse in other types of polyps, suggesting a higher risk associated with non-pedunculated lesions. Both sexes differed less than suggested based on epidemiological statistics.