Increased Prevalence of Advanced Histologic Features in Small and Diminutive Polyps in Patients Undergoing Surveillance and Diagnostic Colonoscopy.

Objective: Studies addressing small and diminutive polyps and their potential of harboring advanced histologic features (AH) are scarce in Hispanics. We aimed to determine the prevalence of AH in a cohort of Hispanics.

Methods: A retrospective review of medical records of patients who had a colonoscopy from 2005 through 2010. The data collected included demographics, indications, history (personal/family) of colon cancer and/or polyps, and polyp histology. Polyps with high-grade dysplasia, prominent villous component, adenocarcinoma or serrated were classified as having AH.

Results: The population comprised 1884 patients, and 3835 polyps were evaluated; 63.3% were diminutive (1-5 mm), 22.7% small (6-9 mm), and 13.9% large (≥10 mm). The prevalence of AH for small and diminutive polyps were 4.9% and 1.1%, respectively. Of the polyps with AH, 11.9% were diminutive and 19.6% small. Small polyps were 5.04 times more likely to harbor AH than were diminutive polyps. Distal rather than proximal polyps were more likely to harbor AH. Furthermore, AH was >7 times more common in small (6-9 mm) polyps identified during diagnostic or surveillance colonoscopies compared to screening colonoscopies.

Conclusion: The prevalence of AH was significantly associated with size, location (distal), and procedure indication. Although diminutive polyps (<6 mm) were less likely to harbor AH, the risk for non-Hispanics was higher than previously reported. The "resect and discard" strategy for polyps ≤ 1 cm should be used with caution in ethnically diverse cohorts, as the risk for AH may be higher in Hispanics than in non-Hispanic Whites.