Glioblastoma multiforme mimicking optic neuritis

PURPOSE: To present a case of glioblastoma multiforme which initially presented with only ophthalmic manifestations. OBSERVATIONS: A 48-year-old man presented with decreased vision and pain with eye movements of the right eye. MRI of the brain showed increased T2/FLAIR signal involving the right optic nerve with no other identified abnormalities. He was treated with intravenous steroids for presumed optic neuritis. His visual acuity then rapidly worsened to no light perception, with new orbital apex symptoms including central retinal artery and vein occlusions and inferior division third and fourth nerve palsies. Repeat MRI with contrast showed perineural enhancement surrounding the right optic nerve and markedly reduced diffusion along its entire course. After an unrevealing initial workup and then a 7 month period during which the patient refused follow up, he re-presented with left sided weakness, headache, and confusion. Repeat brain MRI revealed a large mass involving the right optic nerve, optic chiasm, basal ganglia, corpus callosum and brainstem. Biopsy led to a diagnosis of WHO grade IV glioblastoma multiforme. The disease was poorly responsive to temozolomide, bevacizumab and external beam radiation, and the patient passed away 5 months later. CONCLUSIONS AND IMPORTANCE: Malignant optic glioma of adulthood is a challenging diagnosis with a poor prognosis. This rare case highlights the importance of maintaining neoplasm in the differential for optic neuritis masqueraders.