Clinical Significance Of Isolated Diminutive Colonic Polyps

INTRODUCTION/OBJECTIVES: Several reports have assessed clinical significance of diminutive (1-5 mm) polyps; here we report on the prevalence of advanced histology in patient with "isolated" diminutive polyps, i.e. without associated polyps of larger size. AIMS & METHODS: Retrospective examination of endoscopy records and of histopathology records of patients with polyps of any size. Advanced histology was defined as the presence of high grade dysplasia (HGD) or in situ carcinoma. Polyps were categorized into three groups: diminutive (1-5 mm); small (6-10 mm) and large (11 mm or more). Diminutive Small Large Advanced Carcinoma Number 315 89 67 84 Male (%) 205 (62) 57 (64) 46 (68) 52 (62) Mean age 62.0 67.2 68.7 70.1 % HGD 0.9 11.2 32.8 Not appropriated RESULTS: Data on 2176 consecutive colonoscopies were evaluated; biopsies were performed in 895 (41%); 555 (61%) biopsies evaluated polyps of various size; 315 patients (61%) showed "isolated" diminutive polyps, 89 (16%) patients had small polyps and 67 (12%) had large polyps. Advanced carcinoma was present in 84 (15%) patients. Mean age and prevalence of high grade dysplasia are shown in the table. CONCLUSION: "Isolated" diminutive polyps are at very low risk of advanced histology; small polyps carry a significant risk of advanced histological features. Difference in mean age between groups at different risk of HGD and with patients with advanced carcinoma suggests that progression from diminutive polyps to polyps of larger size and with significant HGD risk might need several (5 or 6) years.