Hamartomatous polyposis syndromes

The hamartomatous polyposis syndromes (HPS) include a small but appreciable number of the gastrointestinal hereditary cancer syndromes and are characterized by the presence of gastrointestinal (GI) hamartomatous polyps. Hamartomatous polyps account for a very small percentage of all GI polyps. They arise from excessive proliferation of the epithelial and stromal cells native to the tissue of origin and contain components from any of the three germ layers forming the intestines. The process underlying the progression of hamartomatous polyps to cancer is not fully understood. HPS occur at approximately one tenth of the frequency of adenomatous polyposis syndromes and account for less than 1% of colorectal cancer cases, although their prevalence may be higher than originally thought. It is now well recognized that these syndromes confer a substantial risk of colonic and extracolonic malignancies, therefore making it important to identify individuals with HPS for further risk management.