Brain scan showing an oligodendroglioma

A glioma, in this case an oligodendroglioma, shows up as a white and orange area on this brain scan. The tumor has displaced a large amount of brain tissue and is spreading.

A glioma is a tumor of glial cells, the supporting cells of the brain. They never metastasize (see cancer), but produce signs of focal damage to the brain, such as weakness, visual disturbance, personal change, or epilepsy, and often a characteristic type of headache. Surgery and radiation therapy may be helpful, but glial cell destruction cannot be reversed.