Basal encephalocele presenting with monocular visual loss.

A 23-year-old male was seen with acute onset of decreased vision in the right eye. There was no associated facial abnormality, optic disc abnormality, or previous history of head trauma. A computerized tomography scan of the head revealed a soft tissue density in the right ethmoidal sinus. Surgical decompression of the ethmoid sinus for a possible pyocele or mucocele revealed the mass to be cerebral cortex. Successful neurosurgical repair of the defect in the cribiform plate and amputation of the abnormal brain tissue was accomplished with restoration of vision.