Paraneoplastic optic neuropathy and autoantibody production in small-cell carcinoma of the lung.

A 59-year-old woman presented with acute-onset, bilateral, painless loss of vision, dysarthria, and ataxia. Ophthalmoscopy showed bilateral optic disc edema. A magnetic resonance scan of the head was normal. Chest radiography showed mediastinal adenopathy. Mediastinoscopy and biopsy identified small-cell carcinoma of the lung. An autoantibody to optic nerve and retina was demonstrated in the patient's serum. An electroretinogram was normal. The patient was diagnosed with a paraneoplastic optic neuropathy and paraneoplastic cerebellar syndrome. After treatment for her lung cancer, the patient remains stable from a visual and neurologic standpoint.