This is the most common type of brain tumor in adults, accounting for more than three of every four malignant brain tumors. These tumors start in glial cells that surround and support nerves. There are different types of gliomas, which will affect the course of your treatment. Among the gliomas:

• Astrocytomas: The most common type of glioma represents about half of all primary tumors found in the brain and spinal cord. They develop in glial cells known as astrocytes, often in the cerebrum. They are more common in middle-aged men.
• Ependymoma: These tumors form in the ependymal cells found in passageways used to move cerebrospinal fluid to your brain. These occur most often in young children. In adults, they are more likely to be found in the spinal cord, where they may cause weakness in parts of the body.
• Glioblastoma: Also known as glioblastoma multiforme, this is the most invasive of glial tumors. They tend to grow quickly and spread to other healthy tissue. There is no cure for these tumors, though treatment can slow their spread. They are more common in men between the ages of 50 and 70.
• Oligodendroglioma: These glial tumors start in cells called oligodendrocytes, which are responsible for making myelin, a substance that protects nerves and helps transmit electrical signals through the brain and spinal cord. These tumors are more common in adults.

This tumor starts in the cerebellum – the lower back of the brain – which helps with muscle coordination, balance and movement. The tumor may spread through cerebrospinal fluid to other parts of the brain. These are most common in young children.

This rare non-Hodgkin lymphoma is caused by cancerous lymph tissue cells forming in the brain or spinal cord. The cancer can also spread to the brain from other parts of the body. This is found most often in people over the age of 50.

These tumors form under the brain and the bottom of the skull, making them difficult to treat. While they are often benign, they can be life-threatening because of their proximity to important nerves and blood vessels. Among the skull base tumors:

• Chordoma: These benign skull base tumors are commonly found at the base of the skull or lower spine.
• Pituitary tumor: These are unusual growths (mostly benign) found in the pituitary gland, which is behind the nose and is responsible for making and storing hormones.
• Craniopharyngioma: These are usually benign but difficult to remove since they tend to form from the pituitary gland.
• Meningioma: This usually benign tumor forms in the membrane that surrounds the brain and spinal cord.