MedGen

Hereditary mixed polyposis syndrome-2 (HMPS2) is characterized by colonic polyps of mixed hyperplastic, adenomatous, and occasional juvenile types. Polyposis eventually progresses to colorectal cancer (Cao et al., 2006). For a discussion of genetic heterogeneity of HMPS, see HMPS1 (601228). [from OMIM]

The presence of more than 5 juvenile polyps of the colon. The term juvenile polyps refer to a special histopathology and not the age of onset as the polyp might be diagnosed at all ages. The juvenile polyp has a spherical appearance and is microscopically characterized by overgrowth of an oedematous lamina propria with inflammatory cells and cystic glands. [from HPO]