[Idiopathic inflammation of the optic nerve simulating optic nerve sheath meningioma].

A case of idiopathic inflammation of the optic nerve (perioptic neuritis) which simulated optic nerve sheath meningioma is reported and the literature reviewed. In this case, idiopathic inflammation of the optic nerve caused enlargement of the nerve and its sheath, showing a tubular diffuse thickening with a central hypodense area (tram-tracking sign). thus mimickling the cancers morphology idiopathic perioptic neuritis is an important condition for, the differential diagnosis of visual loss when CT demonstrates enlargement of the optic nerve.