Serrated polyps of the colon.

Until recently, colonic polyps were traditionally classified as either hyperplastic or adenomatous, and only the latter were believed to have the potential to progress to carcinoma. However, it is now appreciated that a subset of serrated polyps also appear to have malignant potential. Serrated polyps are a heterogeneous group of colon polyps that include hyperplastic polyps, sessile serrated adenomas (SSAs), traditional serrated adenomas, and mixed polyps. Insights into these polyps were derived, in part, from studies of patients with the hyperplastic polyposis syndrome. SSAs show a predilection for the right colon, have a distinct histology, and their molecular genetic profile has recently been linked to a pathway for colon tumorigenesis that is characterized by microsatellite instability. Based upon available evidence, it is recommended that patients with serrated adenomas undergo colonoscopic follow-up at the same frequency as for conventional adenomas. It is important that physicians are aware of serrated polyps, particularly serrated adenomas and their relationship to colon cancer, and their proper clinical management.