Malignant brain tumors contain cancer cells. They are usually fast growing and spread to nearby healthy tissue. Malignant brain tumors very rarely spread to other areas of the body, but may recur (come back) after treatment. Benign (non-cancerous) brain tumors are sometimes called malignant if they damage the brain because of their size or location.

Doctors at the OHSU Brain Institute are experts at treating all types of brain and central nervous system tumors, including malignant tumors.

Types of malignant brain tumors include:


A glioma is the most common type of primary brain tumor (tumor that starts in the brain). Gliomas start in glial cells, which are the supportive tissue of the brain.

Doctors classify gliomas by the type of glial cells that started the tumor and where the tumor is located in the brain.

Types of gliomas are:


Astrocytomas are glial cell tumors that start from connective tissue cells called astrocytes. These cells can be found anywhere in the brain or spinal cord.

Astrocytomas are the most common type of childhood brain tumor and the most common type of primary brain tumor (tumor that starts in the brain) in adults. They are classified as high-grade, medium-grade or low-grade. High-grade astrocytomas (glioblastomas) are the most malignant of all brain tumors.

Astrocytomas also classified based on where the tumor is located. In children, they are most common in the cerebellum (bottom part of the brain). These tumors are called cerebellar astrocytomas. They usually cause symptoms of increased intracranial pressure (pressure inside the skull), headache and vomiting. Cerebellar astrocytomas can also cause problems with walking and coordination and may cause double vision (seeing double).

In adults, astrocytomas are more common in the cerebral hemispheres (cerebrum, or main part of the brain). They often cause increased intracranial pressure (pressure inside the skull), seizures or behavior changes.

Brain stem gliomas

Brain stem gliomas are tumors in the brain stem (the part of the brain that connects to the spinal cord). Most brain stem tumors cannot be removed with surgery. This is because they are deep inside the brain and because the brain stem controls basic body functions such as breathing and sleep. Operating in this sensitive area is very difficult, and can't always be done safely.

Brain stem gliomas almost always occur in children. Children of school age are affected most often. Symptoms may include:

  • Double vision (seeing double)
  • Trouble moving the face or one side of the body
  • Problems with walking and coordination


Ependymomas are tumors that start from glial cells. They are most common in the lining of the ventricles (fluid-filled spaces in the brain) or the spinal cord. In children, they are usually near the cerebellum (bottom part of the brain). An ependymoma blocks the flow of cerebrospinal fluid (fluid around the brain and spinal cord). This raises intracranial pressure (pressure inside the skull).

Ependyomomas are most common in children younger than 10. They can grow slowly compared to other brain tumors but may recur (come back) after treatment. When they do, they are more likely to spread to healthy tissue and are more difficult to treat. Two percent of brain tumors are ependymomas.

Glioblastoma multiforme (GBM)

Glioblastoma multiforme is the most invasive (likely to spread) type of glial tumor. These tumors usually grow rapidly and spread to healthy tissue. The prognosis (how well the doctor expects you to recover) is not good.

Glioblastoma multiforme may be made up of several different kinds of cells, such as astrocytes and oligodendrocytes. GBM is more common in people aged 50 to 70. More men than women have GBM.


Medulloblastomas usually develop in the cerebellum (bottom part of the brain). They are most common in children. They are high-grade tumors (many abnormal cells) but usually get better (shrink or go away temporarily or permanently) with radiation and chemotherapy.


Oligodendrogliomas develop from the supporting cells of the brain. They are found commonly in the cerebrum (main part of the brain). Common symptoms of an oligodendroglioma include:

  • Seizures
  • Headache
  • Weakness
  • Behavior changes
  • Sleepiness

People with oligodendrogliomas have a better prognosis (how well the doctor expects you to recover) than for most other types of glioma. However, this type of tumor can become more malignant (cancerous) with time. About 3 percent of brain tumors are oligodendrogliomas.

Optic nerve gliomas

Optic nerve gliomas are in or around the optic nerves (nerves that run from the eyes to the brain). They often occur in people with neurofibromatosis, a genetic (inherited) condition that makes brain tumors more likely to develop.

Optic nerve gliomas usually cause vision loss and hormone problems because these tumors are located in the same area of the brain as glands that control hormone production. Because they grow near sensitive structures, optic nerve gliomas can be difficult to remove with surgery.

Other Types of Brain Tumors

Adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is a rare type of malignant (cancerous) tumor. It develops from glands that produce secretions (fluids) such as breast milk or mucus. ACCs are most common in the salivary glands (glands that make saliva). It can also develop in the trachea (windpipe), lacrimal glands (glands that make tears) breast, skin and vulva. Doctors recognize this tumor by how its cells look under a microscope.

Chondrosarcoma of the skull

Chondrosarcoma is a malignant (cancerous) tumor that is usually found in the cartilage (connective tissue) of the femur (thigh bone), arm, pelvis, knee and spine. Chondrosarcoma can also start in cartilage at the base of the skull.


Esthesioneuroblastoma is a rare cancer of the upper portion of the nasal cavity (area inside your head and above and behind the nose).


Hemangioblastomas are slow-growing tumors that are usually located in the cerebellum (bottom part of the brain). They start from blood vessels and can be large. Someone with a hemangioblastoma often has a cyst (closed sac containing air, fluid or tissue) at the same time.

Hemangioblastomas are more common in people ages 40 to 60. More men than women have hemangioblastomas.

Rhabdoid tumors

Rhabdoid tumors are rare, highly aggressive tumors that usually spread through the central nervous system. They often appear in many places in the body, especially in the kidneys. More children than adults have rhabdoid tumors, but they can also occur in adults.