Juvenile polyposis syndrome
（重定向自Juvenile polyposis）
Juvenile polyposis syndrome is a syndrome characterized by the appearance of multiple juvenile polyps in the gastrointestinal tract. Polyps are abnormal growths arising from a mucous membrane. These usually begin appearing before age 20, but the term juvenile refers to the type of polyp, not to the age of the affected person. While the majority of the polyps found in Juvenile Polyposis Syndrome are non-neoplastic, hamartomatous, self-limiting and benign, there is an increased risk of adenocarcinoma.