Chiasmatic and hypothalamic extension of optic nerve glioma.

An 11-year-old boy was found to have a left optic nerve glioma confined to the orbit and optic canal by clinical examination and computed tomographic (CT) scanning. Repeated neuroradiologic examinations demonstrated intracranial extension of tumor to involve the hypothalamus and third ventricle. Following craniotomy and verification of the diagnosis of glioma by biopsy, the patient underwent a course of radiotherapy that resulted in marked tumor regression. The potential for growth of optic nerve gliomas mandates careful neuroradiologic follow-up regardless of whether there is ophthalmologic deterioration. The natural history of "optic gliomas" remains unknown.