Risk of villous histology or high grade dysplasia in patients with diminutive polyps: influence of number of polyps

INTRODUCTION/OBJECTIVES: Current recommendations on post-polypectomy surveillance recommend shorter intervals in case of 3 or more polyps, irrespectively of histological findings (see reference below). These recommendations doesn't differentiate between diminutive (1-5 mm) polyps and polyps of larger size (>5 mm). AIMS & METHODS: Aim of the present study was to assess, in a group of patients with "isolated" diminutive polyps, i.e. without associated polyps of larger size, if the presence of 3 or more diminutive polyps is associated with higher number of polyps with villous histology (VH) or high grade dysplasia (HGD). Retrospective examination of endoscopical records and of histopathological records of patients with diminutive polyps. RESULTS: 315 patients with "isolated" diminutive polyps were identified; 171 patients showed neoplastic (i.e.adenomatous) histology, while remaining showed hyperplastic histology or absence of polypoid features at histology. Data on prevalence of villous component at histology according to number of polyps detected are shown in the table. N° of patients VH HGD TOT N° of polyps (%) 1 polyp 97 6 1 7 (7.2) 97 2 polyps 43 9 0 9 (20.5) 86 >2 polyps 31 1 0 1 (3.0) 112 Prevalence of villous histology or HGD according to number of diminutive polyps was 16/140 (11.4%) in patients with one or two diminutive polyps and 1 /112 (0.8%) in patients with 3 or more polyps. CONCLUSION: Number of diminutive polyps found in a single patient does not seem to affect risk of villous histology or high grade dysplasia in diminutive polyps. Further studies are needed to assess if current recommendations on 3-year intervals of surveillance for patients with 3 or more polyps can apply to patients with "isolated" diminutive polyps.