Familial Adenomatous Polyposis

It is a condition characterized by the presence of numerous internal polyps,especially a hereditary disease which affects the colon and in which the polyps may become malignant.

Symptoms: patients may experience blood in the stool, diarrhea, mucous discharge, crampy abdominal pain, anemia, weight loss and intestinal obstruction.

Diagnosis: igmoidoscopy. A flexible tube is inserted into your rectum to inspect the rectum and sigmoid ? the last two feet of the colon. At Mayo, sigmoidoscopy is used to screen at-risk children who haven't yet developed polyps. Colonoscopy. A flexible tube is inserted into your rectum to inspect the entire colon. At Mayo, colonoscopy is used after polyps start growing and after age 18, and if attenuated FAP is suspected or already diagnosed. Esophagogastroduodenoscopy (EGD) and side-viewing duodenoscopy. Two types of scopes are used to inspect your esophagus, stomach and upper part of the small intestine (duodenum and ampulla). The doctor may remove a small tissue sample (biopsy) for further study. CT or MRI. Imaging of the abdomen and pelvis may be used, especially to evaluate desmoid tumors.

Treament: Chemotherapy with doxorubicin and dacarbazine may be attempted if no response is observed with other therapies.

Epidemology: In 5-30% of FAP patients, no APC mutation is identifiable by current genetic testing. In 2003, it was shown that 'APC-negative' FAP patients may carry biallelic mutations in a different gene, the MYH gene. Genetics of FAP will be discussed in relation to its present clinical applications. If the hereditable mutation(s) is/are known in a family, it is possible to plan endoscopic surveillance only for those who actually inherited the mutation(s).