polyposis

Polyposis is a condition characterized by multiple polyps arising from mucosal surfaces, most often in the gastrointestinal tract, especially the colon and rectum. Polyps are growths of tissue that can be benign but may increase cancer risk, particularly when many are present or when they are part of a hereditary syndrome.

Causes and syndromes: Polyposis can occur sporadically or as part of inherited disorders. Notable hereditary forms include familial adenomatous polyposis (FAP) due to APC gene mutations, MUTYH-associated polyposis, Peutz-Jeghers syndrome (STK11), juvenile polyposis syndrome (BMPR1A or SMAD4), and Cowden syndrome (PTEN). Cronkhite-Canada syndrome is a sporadic, nonhereditary form with diffuse GI polyposis and extraintestinal findings. Some cases are grouped as serrated polyposis syndrome.

Clinical features and diagnosis: Many people with polyposis have no symptoms; polyps can cause occult blood loss, anemia, abdominal pain, or obstruction. Diagnosis is by endoscopic evaluation with biopsy of polyps and histologic analysis; genetic testing is used when a hereditary syndrome is suspected. Imaging may assess polyps in the small intestine or evaluate complications.

Management and prognosis: Treatment includes removal of polyps and ongoing surveillance with endoscopy to detect new lesions. In FAP and some other syndromes, prophylactic surgery may be indicated. Surveillance strategies and cancer risk vary by syndrome; overall prognosis is related to the likelihood of colorectal or other cancers and to the effectiveness of management.