Öz
A 40-years old female patient applied with complaining of a progressive vision loss for 3 months. Systemic symptoms were; headache, tingling in her hands and feet and pain during eye movements. Visual acuity was hand motion on the right eye, 20/20 on the Snellen chart on the left. There was relative afferent pupillary defect on the right eye. In fundoscopic examination, disc edema was met on the right eye and left eye’s fundus examination was normal.
A prolongation of p100 wave latency in the Visual Evoked Potentials examination and total visual field defect on automated perimetry test were seen on the right eye. The patient was hospitalized with a pre-diagnosis of optic neuritis. Orbita Magnetic Rezonans was reported the optic nerve sheath menengioma (ONSM). Atypical clinical presentation of an ONSM case that mimiced as optic neuritis, extended to the optic chiasm and lead to a progressive visual loss in a period of 3 months is presented. It is crucial to recognize atypical ONSM cases by the guidence of imaging techniques.