Malignant ependymomas in a patient with Turcot's syndrome: case report and management guidelines.

BACKGROUND: Turcot's Syndrome is the association of multiple adenomatous polyps of the colon with a primary tumor of the central nervous system. We present the first reported case of Turcot's Syndrome in a patient with malignant ependymomas. Recent advances in the elucidation of the genetic basis for the hereditary forms of colon cancer have provided a clearer understanding of the etiology of Turcot's Syndrome. This new information is relevant to the neurosurgical community and provides updated guidelines in the diagnosis and management of patients with this complex disease process.
RESULTS: Turcot's Syndrome is related to two distinct genetic errors. The first involves a germ-line mutation in the adenomatous polyposis coli (APC) gene, which is postulated to act as a tumor suppressor gene. The second is a germ-line defect in one of a group of genes responsible for DNA nucleotide mismatch repair.
CONCLUSION: The elucidation of the gene defects responsible for the hereditary forms of colon cancer has provided a clearer understanding of the molecular basis of Turcot's Syndrome. Patients with hereditary forms of colon cancer and neurologic symptoms require immediate and thorough investigation because of their significantly increased risk of developing CNS tumors. Previously healthy patients diagnosed with a CNS tumor with a family history of adenomatous polyposis coli should undergo screening and surveillance colonoscopy as the CNS lesion may precede colonic symptoms. CNS screening guidelines for asymptomatic patients with adenomatous polyposis coli requires further risk analysis studies. All patients diagnosed with Turcot's Syndrome should be tested for the gene defect, including the CNS tumor tissue to provide further data on the genetic relationship between Turcot's Syndrome and the hereditary forms of colon cancer.