Familial adenomatous polyposis and benign intracranial tumors: a new variant of Gardner's syndrome.

INTRODUCTION: Familial adenomatous polyposis (FAP) is associated with malignant tumors of the central nervous system, predominantly medulloblastomas and glioblastoma multiforme (Turcot's syndrome) and with craniofacial osteomas (Gardner's syndrome). This report details the occurrence of benign, intracranial tumors in two related individuals with Gardner's syndrome, an association not previously described.

PATIENTS AND METHODS: A 57-year-old woman (the propositus), her sister, two of her nieces and one of her grandnephews were previously diagnosed with Gardner's syndrome. The propositus came to neurosurgical attention because of vertigo associated with what proved to be an epidermoid cyst of the cerebellopontine angle. Her unaffected children and her relatives with Gardner's syndrome were examined and underwent computed tomography or magnetic resonance imaging.

RESULTS: A 39-year-old woman with Gardner's syndrome, the niece of the propositus, was found to harbor an asymptomatic left frontal meningioma.

DISCUSSION: Familial adenomatous polyposis, Gardner's syndrome, and that variant of Turcot's syndrome in which medulloblastoma predominate, are associated with a mutation of the adenomatous polyposis coli gene. The demonstration that patients with Gardner's syndrome can also have benign, nonneuroglial, intracranial tumors adds to the previously known extracolonic lesions associated with FAP. The molecular characterization of our patients should reveal if benign intracranial tumors represent a pleiotropic manifestation of the adenomatous polyposis coli gene mutation or if other genes are implicated.