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| CT post-contrast | T1 pre-gad | T1 post-gad with fat sat |
Diagnosis: Optic nerve glioma
The peak age for ONG is 5 years old with girls more often affected. Patients may present with proptosis or decreased visual acuity. One half of optic nerve gliomas enhance and calcification is unusual. The tumor most commonly has a tubular appearance with enlargement of the optic nerve and may extend into the chiasm and the optic radiations. Up to 15% of patients with neurofibromatosis type I have optic nerve gliomas, while the converse is true 25% of the time. The differential is limited for this classic appearance. Optic neuritis may cause mild enhancement and enlargement of the optic nerve and chiasm, but not this dramatic. Optic nerve sheath meningiomas are usually seen in middle aged woman but they may occur in children with neurofibromatosis type II. Meningioma is the second most common primary neoplasm of the optic nerve behind ONG. Optic nerve sheath meningiomas intensely enhance and produce a characteristic "tram track" appearance on axial images due to enhancing tumor surrounding the non-enhancing optic nerve. They rarely extend through the optic canal. Related Cases
