Colonoscopy in Polyposis Syndromes

The gastrointestinal (GI) polyposis syndromes encompass a range of disorders characterized by polyp formation in the GI tract. The polyposis syndromes are traditionally classified by the predominant histological type of polyp. This chapter explores the primary GI polyposis syndromes and the role of colonoscopy in these syndromes, focusing predominantly on the best-characterized syndromes. Many of these syndromes are multisystem disorders and the management of extra-colonic manifestations can be as, or more important. A clinical diagnosis of adenomatous polyposis syndrome is traditionally made when there are more than 100 adenomas in the colorectum. The serrated spectrum of polyps includes sessile serrated lesions, hyperplastic polyps, and traditional serrated adenomas. Hereditary mixed polyposis syndrome was first described clinically as causing multiple polyps and being associated with an increased risk for colorectal cancer (CRC). Surveillance is recommended with a view to CRC prevention or early detection.