POLYPOSIS-COLI, CRANIOFACIAL EXOSTOSIS AND ASTROCYTOMA - THE CONCOMITANT OCCURRENCE OF THE GARDNERS AND TURCOT SYNDROMES

BACKGROUND Up to 60% of the patients with known adenomatous polyposis coli may present hyperostosis of the skull and facial bones, and/or a susceptibility to fibromas. This is known as the Gardner's syndrome, a nd is considered as an allelic variant of familial adenomatous polypos is (FAP). Also, although very rare, an adenomatous polyposis coli may occur with malignant tumors of the central nervous system, known as Tu rcot syndrome. If both syndromes are different phenotypic presentation of FAP, this would explain a simultaneous occurrence. METHOD We repor t the history of a patient who showed clinical signs of the simultaneo us occurrence of both Gardner's and Turcot syndromes. The syndromes ar e compared, and in view of the literature, a genetic explanation for t he concomitant occurrence is discussed. RESULTS Evidence obtained from the literature to consider Turcot syndrome as a phenotype of FAP is a s follows: (1) The occurrence of Gardner's and Turcot syndromes in one family, but in different members; (2) The presence of congenital hype rtrophic retinal pigmented epithelium (CHRPE), which correlates with t he expression of polyps in FAP patients, in both syndromes; (3) Linkag e of the Turcot phenotype to the adenomatous polyposis coli locus by g enetic markers. Evidence obtained from this case report indicates that there is a manifestation of both syndromes in one patient together wi th a positive family history for FAP. CONCLUSION This concomitant occu rrence of both Gardner's and Turcot syndromes in one patient clinicall y supports genetic and ophthalmic investigation to consider Turcot syn drome (like Gardner's syndrome) as a phenotypic variant of FAP. Patien ts with FAP should be examined for the presence of Gardner's syndrome. In case a Gardner's syndrome is suspected, a computed tomography scan of the brain is recommended because of the possible existence of a si multaneous Turcot syndrome.