Small Polyps of the Colon: The Wolf in Sheep's Clothing

Abstract

Introduction: The importance of the small colonic polyps has become a controversial issue due to the implementation of new screening methods for colorectal cancer that could overlook these lesions. The prevalence of advanced histological features (AHF) (villous component, high grade dysplasia) in this type of polyps is not precisely known. Aim: To determine the prevalence of AHF in small and diminutive colonic polyps. Methods: Those patients who had undergone a videocolonoscopy and presented small (<9 mm) or diminutive (<6 mm) polyps were identified. Each polyp was analyzed, and the outcomes were expressed in percentages with their corresponding confidence intervals 95%. A multi-variate analysis of logistic regression was carried out to search for independent endoscopic predictors of AHF. Results. In 650 analyzed patients, 1212 polyps were found, 330 ≥ than 1 cm, 661 diminutive polyps, and 214 small polyps. The media age of the patients with diminutive polyps was 63 years old, 51% were men, and the most frequent polyps were hyperplastic (HP) (45%), tubular adenomas (TA) (38%), tubulovillous adenomas (TVA) (11.5%), and serrated polyps (SP) (3%). The AHF prevalence in this group was 3.5%, from which 21% were resected with a snare loop, and 8% were elevated with saline solution and stained with Indian ink. Resection was completed in only 25% of the cases. The media age of the patients with small polyps was 63 years old, 54% were men, and the most frequent polyps were TVA (35%), HP (28%), TA (25%), and SP (6%). The prevalence of AHF polyps was 14%, 90% had been resected with a snare loop, 40% elevated with saline solution and stained with Indian ink. Resection was completed in half of the cases. In the uni-variate analysis, the following factors were AHF predictors: endoscopist's presumption, (OR 3.8 IC 2.2-6.6), and the presence of 3 or more polyps in the rectosigmoid area, with an absence of other polyps bigger than 1 cm in the rest of the colon (OR 0.012, IC 0.009-0.8). In the multi-variate analysis, the following factors were independent predictors of AHF: the presence of more than 5 polyps (OR 8, IC 3-25) and the sessile morphology (OR 0.20, IC 0.10-0.38). Conclusion. There is a significant percentage of AHF in small polyps and a lower one in tiny polyps. The resection margin could not be established in most of the polypectomies. The polyps' detection and resection strategies can still be optimized.