High-grade gliomas are tumors of the glial cells, cells found in the brain and spinal cord. They are called “high-grade” because the tumors are fast-growing and they spread quickly through brain tissue, which makes them hard to treat. The tumors occur in children of all ages, from infants to adults.

High-grade gliomas are rare, with only 360 to 400 new cases occurring each year in North America. They occur equally in boys and girls.

High-grade gliomas are classified by their location and by how they appear when examined under a microscope. Classifying the tumor helps determine how the disease will progress, and helps identify the best treatment for it. Although the outlook for high-grade gliomas is generally poor, some children can be cured.