A 68-year-old man developed subacutely bilateral loss of visual acuity without any other neurological sign. Magnetic resonance images showed some small scattered periventricular white matter T2 hypersignals. On spinal fluid analysis a mononuclear pleocytosis and an oligoclonal gamma-pattern was found. Treatment with intravenous corticosteroids had no effect. The clinical situation deteriorated and the patient died of bronchopneumonia. Postmortem examination revealed manifest metastatic invasion of both the optic nerves by a non-detectable primary tumor.