Ordering correct imaging studies key to diagnosing primary optic nerve tumors

Chicago-Magnetic resonance imaging (MRI) is the procedure of choice for evaluating patients with possible primary optic nerve tumors. Computerized axial tomography (CT), however, may also useful for showing calcification in meningioma, explained Andrew G. Lee, MD, professor of ophthalmology, neurology, and neurosurgery, University of Iowa Hospitals and Clinics.

The two primary optic nerve tumors are optic nerve glioma, usually found in children, and optic nerve sheath meningioma, seen in middle-aged women, said Dr. Lee, during a session on therapeutic neuro-ophthalmology at the subspecialty day meeting in Chicago.

Clinical findings for primary optic nerve tumors include ipsilateral loss of visual acuity and/or visual field, dyschromatopsia, relative afferent pupillary defect, proptosis, optic disc edema, or atrophy.

“We don’t usually have to perform a biopsy of these lesions. The imaging alone is normally characteristic enough to make the diagnosis of glioma or meningioma,” Dr. Lee said.

“The head and orbit are required in your imaging study. Be sure to order a fat suppression and gadolinium contrast,” he said. “CT scan still might have a role for calcification in meningioma.”