[Serrated polyps is a hidden but common cause of colorectal cancer]

The concept that serrated polyps can cause colorectal cancer is relatively new and not very well-known. Serrated polyps are difficult to identify and treat endoscopically. This together with the fact that premalignant serrated polyps are mainly located in the proximal colon might help explain why colonoscopy is less effective against right-sided compared to left-sided colorectal cancers and why interval cancers usually appear in the proximal colon. In fact, serrated polyps may cause up to one third of all sporadic colorectal cancers. In spite of this, the aetiology, incidence, prevalence and natural history of serrated polyps remains elusive. Endoscopists and pathologists must have a good understanding of serrated polyps in order to effectively diagnose, treat and follow up these lesions. This review focuses on the pathophysiology, types, work-up, treatment and follow-up of serrated polyps in the colon and rectum.