Sessile serrated adenomas strongly predispose to synchronous serrated polyps in non-syndromic patients.

AIMS: To determine the prevalence of various colonic polyps removed during a recent 8-month period; to determine the interobserver agreement in the diagnosis of serrated polyps; and to determine if harbouring a sessile serrated adenoma (SSA) predisposes to the presence of synchronous polyps with similar histology.

METHODS AND

RESULTS

All polyps resected during an 8-month period at a single tertiary medical centre were analysed. We also analysed all polyps in patients with an SSA or SSA with dysplasia since 2003. SSAs accounted for 4.3% of colonic polyps removed during an 8-month period. A review of 276 serrated polyps by two pathologists revealed good interobserver agreement (kappa = 0.66). Patients with one SSA were more likely to harbour additional serrated polyps. After removal of the index SSA, 18% of their remaining polyps were SSAs, SSAs with dysplasia, and traditional serrated adenomas, contrasting with the approximately 5% prevalence of these polyps in the control population. The hyperplastic polyps in the study population were also twice as likely to occur proximal to the splenic flexure.

CONCLUSIONS

These data indicate that there is a strong colonic mucosal field defect in patients with sporadic SSAs that predispose them to develop additional serrated polyps.