Sphenoid sinus carcinoma mimicking retrobulbar optic neuritis.

Sphenoid sinus carcinomas occur rarely compared with other sinonasal tumors. A case of sphenoid sinus squamous cell carcinoma presenting with acute, isolated optic neuropathy and visual loss is presented herein along with the related literature. A 37-year-old man with sudden decrease in visual acuity in his left eye of 15 days' duration was referred. He had received high-dose intravenous corticosteroid therapy with the provisional diagnosis of retrobulbar neuritis, and his visual acuity had temporarily improved at this time. Magnetic resonance study showed a space-occupying lesion in the left posterior ethmoid and sphenoid sinuses, adjacent to the intracanalicular optic nerve, and an increase in optic nerve signal intensity. An excisional biopsy of the sphenoid lesion revealed squamous cell carcinoma. After stereotactic radiotherapy and chemotherapy following surgery, a total loss of vision and optic atrophy developed in the left eye. No other complication, tumor recurrence, or metastasis occurred during 30 months of follow-up.