You have recieved a verification code on your email..!
Appointment
Orbital Tumors - Optic Nerve Glioma
Clinical Symptoms
decreased visual acuity
minimal proptosis
restricted, decreased eye movement
strabismus
Etiology
neoplasm of the optic nerve
may also be called juvenile pilocytic astrocytoma
Optic nerve glioma in adults are glioblastoma
Optic nerve glioma is the most common cause of optic nerve enlargement
it accounts for 80% of optic nerve tumors
1% of all intracranial tumors
2% of childhood intraorbital masses
Demographics
80% are in children under 10 years old
peak age is 5-8
90% of patients are under the age of 20
more common in females
10-50% are in neurofibromatosis patients, especially if bilateral
15% of NF patients have an optic glioma
Clinical Course
Optic nerve gliomas grow very slowly and have similar pathology as juvenile pilocytic astrocytomas of the cerebellum.
typically intraorbitally and grow in a fusiform shape
25% are limited to the orbit
malignant degeneration is very rare in children
if the tumor begins in the chiasm, it is likely to invade surrounding parenchyma regardless of age
Imaging
On MRI, there is usually mild contrast enhancement. The affected optic nerve should be greater than 3 mm in diameter, or 1 mm wider than the unaffected side. It should be hypo- to isointense to muscle on T1 and hyperintense on T2. Fat supression sequences should be performed to see the entire extent of the lesion since it could appear to be more extensive than it is on T2-weighted images secondary to edema