Objective: To determine the prevalence of serrated adenomas (SA), the frequency of high grade dysplasia (HGD) and adenocarcinoma in these polyps, and the association with synchronic (SNL) and metachronic neoplastic lesions (MNL).
Methods: Reports from patients undergoing colonoscopy and polypectomy from January 2003 to April 2010, were obtained from our electronic database. SA were reanalyzed by two pathologists and classified on the basis of Snover's diagnostic criteria. The prevalence of these polyps and the clinical and endoscopic features were determined. SNL were defined by adenomas, cancer or advanced neoplastic lesions (ANL) (> 1 cm, HGD and/or >75% of villous component) in the same colonoscopy. MNL were identified in patients who underwent surveillance colonoscopies. An univariate and multivariate analysis was performed, looking for independent predictors of HGD/ cancer, SNL and MNL in patients with SA.
Results: The prevalence of SA was 0.87%. The mean age was 60 years old and 50.5% of patients were women. Most of the polyps were sessile (67%), small (63%) and located in ceco-ascending colon (47%). We found HGD in 4.4% ofSA and no adenocarcinoma. SNL was found in 31% ofpatients: 46% adenomas, 40.5% ANL and 13.5% adenocarcinoma. MNL was found in 29% of patients: 25% SA, 31% adenomas, 44% ANL and 0% adenocarcinoma. Age over 60 years old was significantly associated with MNL [Odds ratio 3.7 (95% confidence interval 1.16-11.8)] and polyp's size higher than 1 cm with sessile SA histology [Odds ratio 8 (95% confidence interval 1.28-49.4)].
Conclusion: The prevalence of SA was low. We found an association with neoplastic lesions. Therefore, it is important to establish specific guidelines for the management of these polyps.