Optic pathway gliomas in neurofibromatosis.

Two patients, a 5-year-old girl and a 3-year-old boy, with documented neurofibromatosis (NF-1) and visual pathway gliomas are reported. In the first patient, the tumor was a typical pilocytic astrocytoma confined to the proximal half of the right optic nerve just near the globe. The tumor was excised; after a follow-up of 7 years recurrence has not occurred. The second patient had a glioma of the left optic nerve, with involvement of the chiasm, optic tracts, probably lateral geniculate body, optic radiations and basal ganglia. Biventricular hydrocephalus, possibly due to the occlusion of Monro's foramina, was also noted. In this case, magnetic resonance imaging (MRI) was superior to computed tomography for visualizing the posterior extension of the lesions. The patient received X-ray therapy and after a follow-up of 3 years the clinical symptomatology remains stationary. It is suggested that the optic pathway involvement detected by MRI may represent a dysplastic element NF-1 rather than a truly neoplastic change.