The Virtual Hospital: Disease: Optic Glioma

Radiology Resident's Case of the Week

Disease: Optic Glioma

July 21,1995

Michael Rubin, M.D.
Peer Review Status: Not reviewed

Clinical Sx:
Visual field loss is common in 88% of patients at presentation. Pain and headache are presenting symptoms in 30% of patients with chiasmal involvement. Symptoms of intraaxial involvement include nystagmus, seizures, hydrocephalus, and hypothalamic sig ns.

Etiology/Pathophysiology:
71% of cases occur in the 1st decade of life with no sex predominance. 15% of patients with Neurofibromatosis type 1 will develope optic glioma. At presentation 1/4 of the neoplasms are confined to the optic nerve and 3/4 extend into the optic chiasm.

Pathology:
Optic gliomas arise from the supporting astrocytes of the optic nerve with most being classified as benign pilocytic astrocytomas. The cells may extend into the subarachnoid space which provokes proliferation of fibrovascular tissue and meningothelial cells.

Miscellaneous:

Imaging:
Plain film: Classic findings are enlargement of the optic foramen and a J-shaped sella.

CT: Most optic gliomas demonstrate enlargement of the optic nerve or chiasm with no to moderate contrast enhancement.

MRI: T1 weighted images demonstrate enlargement of the optic nerve with normal to slightly hypointense signal.

T2 weighted imgages demonstrate hyperintense signal. Contrast enhancement is variable.

DDx:
Optic meningioma Dural ectasia of the optic nerve sheath

Key references:

Optic Nerve Gliomas and Meningiomas. Neuro-opthalmology. Neurologic Clinics. Dutton, J.J. Vol. 9. No. 1. Feb. 1991
Gliomas of the Anterior Visual Pathway. Survey of Opthalmology. Dutton, J.J. Vol. 38. No. 5. March-April 1994.

ACR Code:

Keywords:

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