Meningioma: (1) Occurring most often in the middle aged females, this rare, invasive tumor arising from the arachnoidal villi is classified as a primary mengioma if the tumor arises from the meninges surrounding the optic nerve, or secondary if it originates intracranially with secondary extension into the orbit, If the tumor arises form the optic nerve, patients will present with decreased vision, papilledema, optic nerve atrophy and possibly proptosis. CT scanning with contrast will reveal a mass with a lucent center arising form the nerve. Surgical intervention is reserved for tumors that threaten intracranial structures. Back to Orbit