Sunday, January 13, 2008

How to Diagnose Glioma


A glioma is any tumor arising from the glial cells of the brain, pineal gland, posterior pituitary gland, retina or spinal cord. They include astrocytomas, ependymomas and oligodendrogliomas and are the most common primary brain tumor. There are two specific types of gliomas to be discussed: brain stem gliomas and optic gliomas. The following steps will show how to diagnose a glioma.


Difficulty: Challenging



Step One

Expect the symptoms of brain stem gliomas to be dependent upon their growth rate, location and size. These include a host of neurological deficits including, but not limited to, double vision, paralysis, speech problems and difficulty in swallowing. A glioma also may cause hydrocephalus if it blocks the spinal fluid.

Step Two

Observe more specific symptoms in optic gliomas. The most common initial symptom is a tendency to fall forward followed by optic atrophy. A loss of visual acuity also is common but may occur later. A larger lesion may cause a rhythmic oscillation of the eyes if it compresses the optic chiasm.

Step Three

Perform a Magnetic Resonance Imaging (MRI) scan as the diagnostic procedure of choice. An MRI typically shows a brain stem glioma as an expansive, infiltrative tumor. They show as isodense to slightly hypodense on T1-weighted images and hyperdense on T2-weighted images.

Step Four

Use gadolinium enhanced T1-weighted images as the preferred method for optic nerve gliomas. They are usually isodense in the cortex and hypodense in white matter.

Step Five

Determine the histopathology of the tumor. Most gliomas are pilocytic astrocytomas or glioblastomas that are more malignant.

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