Turcot syndrome is characterized by the formation of multiple benign growths (polyps) in the colon that occur in association with a primary brain tumor. These growths are associated with bleeding from the rectum, Diarrhea, Constipation, Abdominal pain, and/or Weight loss. The number and size of these polyps may vary greatly from case to case, ranging from fewer than 10 to more than 100.
Some researchers have separated Turcot syndrome into two forms. type 1 is characterized by the presence of fewer than 100 colonic polyps. These polyps are large in size and more likely to become malignant (cancerous). Type 2 is characterized by smaller, more numerous colonic polyps. This type of Turcot syndrome closely resembles familial adenomatous polyposis. (For more information on familial adenomatous polyposis, see the Related Disorders section of this report.)
Individuals with Turcot syndrome often have neurological abnormalities that vary, depending upon the type, size, and location of the associated brain tumor. In cases of Turcot syndrome, the brain tumor is often a glioma. Additional brain tumors that have been associated with Turcot syndrome include medulloblastomas, glioblastomas, ependymomas, and astrocytomas. Medulloblastomas occur with greater frequency in the type 2 form of Turcot syndrome.
Individuals with Turcot syndrome have a much greater risk than the general population of developing colon cancer later in life. Affected individuals also have a predisposition to develop malignant (cancerous) tumors in areas outside the colon, including thyroid, adrenal, and/or abdominal tumors.
Additional symptoms associated with Turcot syndrome include small, coffee-colored spots on the skin (cafe-au-lait spots), the formation of multiple, benign fatty tumors (lipomas), and/or the development of a type of skin cancer known as basal cell carcinoma. Basal cell carcinoma is characterized by the formation of small, shiny, firm masses of tissues (nodules); flat, scar-like lesions (plaques); or red patches covered by thick, dry, silvery scales on the skin.