An osteolytic meningioma en plaque of the sphenoid ridge.

Meningioma en plaque (MEP) is a rare tumor characterized more by its clinical and biological behavior than its histological appearance. Hyperostosis of the skull is one of the characteristic signs of MEP. This bony change can produce clinical symptoms and signs in MEP by pressing against adjacent structures. The authors report a rare case of an osteolytic MEP extending from the sphenoid wing into the orbital wall, middle fossa, and temporalis muscle.