Case of Optic Nerve Sheath Meningioma

A 32 year old female, known hypothyroid on treatment and no other comorbidities had come with the complaints of reduced vision in the left eye. Opthalmoscopic examination showed optic disc swelling. There was mild proptosis. On computed tomography of brain, there was thickening around the left optic nerve with calcifications. Brain parenchyma was normal. On MRI plain and contrast, there was thickening around the left optic nerve which showed homogenous enhancement post gadolinium contrast administration. This thickening of the optic nerve sheath caused compression and atrophy of the left optic nerve, resulting in the patient's complaints of reduced vision on the left side. Brain parenchyma was normal. There was no intra-parenchymal extension of the lesion. Orbital muscles were normal.