Gardner's syndrome is a variant of familial polyposis associated with desmoid tumors, osteomas of the skull or mandible, and sebaceous cysts. Other rarer variants of familial polyposis involve multiple colonic adenomas and other lesions. Peutz-Jeghers syndrome is an autosomal dominant congenital disease with multiple hamartomatous polyps in the stomach, small bowel, and colon. Symptoms include melanotic pigmentation of the skin and mucous membranes, especially of the lips and gums. Other Polyps Juvenile polyps are usually non-neoplastic, often outgrow their blood supply, and autoamputate at puberty.
Treatment is required only for uncontrollable bleeding or intussusception.
Hyperplastic polyps, also non-neoplastic, are common in the colon and rectum. In Western countries, the colon and rectum account for more new cases of cancer per year than any other anatomic site except the lung. Colorectal cancer is the most frequent cause of death among visceral malignancies that affect both sexes. Populations with a high incidence of colorectal cancer eat low-fiber diets that are high in animal protein, fat, and refined carbohydrates. Carcinogens may be ingested in the diet but are more likely to be produced from dietary substances or from biliary or intestinal secretions, probably by bacterial action.