Background and aims: Aim of the present study is to ascertain the importance of diminutive colorectal polyps and define the need for removal according to their characteristics and malignant potential.
Patients and methods: A total of 4,723 patients who underwent colonoscopy were evaluated and 624 patients with 826 polyps were recorded. There were 352 patients with 443 diminutive polyps, studied according to their distribution. Of these, 371 were removed, histologically examined and correlated to patient characteristics and occurrence of synchronous neoplasms.
Results: Of the right colon polyps, 81/115 were diminutive, versus 362/711 of the left colon (p<0.0001). Adenomas were more common in patients over 50 years of age, (p<0.0001). In all colonic segments, diminutive adenomas prevailed over hyperplastic polyps, whereas the proportion of diminutive adenomas predominated in the right colon (p=0.0015). Adenomas were classified as tubular 39%, tubulovillous 55.7% and villous 5.3%. The degree of dysplasia was mild in 45.5%, moderate in 51% and severe in 3.5%. The prevalence of synchronous neoplasms was 37.4%. They were more frequently found in males over 50 years of age and in patients with diminutive adenomas compared to those with diminutive hyperplastic polyps (p=0.0078).
Conclusions: The majority of right colon polyps are diminutive. The proportion of diminutive adenomas is higher in patients over 50 years and in the right vs left colon. Diminutive polyps should be removed taking into account the high prevalence of adenomas with a villous component and their significant degree of dysplasia.