Optic nerve sheath meningioma: a case report with 15-year follow-up.

Meningiomas are benign neoplastic lesions of arachnoidal cells of the meninges. These tumors may arise wherever meninges exists, such as in the nasal cavity, paranasal sinuses, middle ear, and mediastinum. Optic nerve sheath meningiomas (ONSMs) are usually unilateral and occur predominantly in middle-aged females, although they may be present at any age. We present a case of a 55-year-old female with ONSM diagnosed when she was 40 years old. Diagnosis and follow-up was based on the clinical picture, CT orbit scan, and magnetic resonance imaging.