Glioma

January 12, 2026

This page was reviewed under our medical and editorial policy by Rosalind Munoz, P.A., Department of Medical Oncology & Therapeutics Research, City of Hope^® Cancer Center Duarte.

Glioma is the term for several different kinds of tumors that affect the brain or spinal cord. Although gliomas are the most common type of brain tumor, they are still relatively rare, affecting only 6 in every 100,000 Americans every year.

What Is Glioma?

Gliomas are brain tumors that begin in a type of cell called the glial cells. These cells form part of the tissue that helps protect and support the brain and its neurons. There are three types of glial cells: astrocytes, oligodendrocytes and ependymal cells. Glioma can develop in any of these types of cells, or in several different types at once. Some glioma types are aggressive while others are slower-growing.

Glioma Symptoms

Some people who develop a glioma brain tumor experience symptoms and others do not. Whether someone experiences symptoms depends on factors such as the size and location of the tumor. However, some of the common symptoms of glioma include:

• Headaches that do not go away and that may be worse in the mornings
• Feeling nauseated or vomiting
• Seizures
• Changes to vision, including blurred vision or double vision
• A feeling of numbness or weakness on only one side of the body
• Personality changes or issues with memory or cognition

Causes and Risk Factors

Gliomas occur when glial cells in the brain or spinal cord begin to grow out of control and form a tumor. Although scientists do not yet fully understand the causes of glioma, there are some risk factors for the disease – which are factors that make it more likely someone may develop glioma in the future. These include having certain genetic conditions, such as:

• Li-Fraumeni syndrome
• Neurofibromatosis type 1 or 2
• Tuberous sclerosis

Diagnosis and Testing

In most cases, the first step in diagnosing glioma is to use imaging techniques to take pictures of the inside of the brain. If a patient shows any signs of unusual growths or tumors, they are usually referred to neuro-oncology experts, who are doctors specializing in cancers and tumors that affect the brain and spinal cord. Some of the tests used to diagnose glioma include:

• Magnetic resonance imaging (MRI), a type of scan that uses powerful magnets to create images of the brain
• Biopsy, which is a procedure to remove some or all of a tumor so that it can be examined in a lab for signs of cancer
• Genetic testing, which can help determine what type of cancer a patient has on a cellular level

Glioma Types

There are several different types of glioma. Glioma types are classified based on what type of glial cell they started in and on any genetic mutations that affect how the tumor grows or behaves.

Astrocytoma

Astrocytoma is a type of glioma that begins in cells called astrocytes. They may also be referred to as IDH mutant astrocytoma, referring to the fact that they are caused by mutations in the IDH gene.

Brain Stem Glioma

Glioblastoma Glioblastoma is a high-grade, fast-growing form of glioma. It may also be referred to as IDH wildtype glioblastoma, because it is caused by mutations in the IDH gene.

Diffuse Intrinsic Midline Glioma (DIMG)

Diffuse intrinsic midline glioma (DIMG) is a type of brain tumor that most often begins in the pons, which is a part of the brain stem. However, it can also affect the spinal cord or other parts of the brain, including the thalamus or cerebellum.

Glioblastoma

Glioblastoma is a high-grade, fast-growing form of glioma. It may also be referred to as IDH wildtype glioblastoma, because it is caused by mutations in the IDH gene.

Gliomatosis Cerebri

Gliomatosis cerebri is a rare form of glioma. It develops in several different kinds of glial cells and in multiple places within the brain at the same time. It is considered a low-grade form of glioma, however, it can cause symptoms in the areas of the brain where tumors develop.

Oligodendroglioma

Oligodendroglioma starts in cells called oligodendrocytes. This type of tumor is categorized either as diffuse (grade 2) or anaplastic (grade 3), depending on how aggressive and fast-growing it is.

Optic Nerve Glioma

Optic nerve glioma develops in the cells of the optic pathway, which play a vital role in how the brain perceives and processes visual stimuli. It is most common in children aged 10 and under and is more likely to affect people with a genetic condition called neurofibromatosis type 1.

Grades

When diagnosing glioma, cancer experts assign a grade to a patient’s glioma. These grades are numbered from 1 to 4, with higher numbers referring to faster-growing, more aggressive tumors.

Low-grade gliomas are those that are diagnosed as grade 1 or grade 2.

• Grade 1 glioma has cells that look mostly normal and is slow growing.
• Grade 2 glioma has cells that look slightly abnormal, may spread to other tissue and may come back as a higher-grade glioma even after treatment.

High-grade gliomas are those that are diagnosed as grade 3 or grade 4.

• Grade 3 glioma has cells that look abnormal and is continuing to grow. It spreads to other tissue and is more likely to come back even after treatment.
• Grade 4 glioma has cells that look very abnormal and it grows quickly. It may also have dead tissue at the center of the tumor.

Doctors may also classify a patient’s glioma using classifications created by the World Health Organization. Classifying glioma is based on factors including:

• The grade of the tumor
• The size and location of the glioma
• What type of cells the glioma began in
• Any genetic changes specific to the patient’s tumor

Glioma Treatment

There are several different treatment options for glioma. A patient’s cancer care team may recommend one or multiple treatments, depending on the grade and type of glioma someone has, as well as their patient’s overall health.

• Neurosurgery is the most common treatment for glioma. The goal of surgery is to remove as much of the tumor as possible. It is sometimes used in combination with chemoradiation or other therapies.
• Chemoradiation is a combination of chemotherapy and radiation therapy. Chemotherapy refers to drugs that target and destroy cancer cells. Radiation therapy is the use of radioactive beams or substances to kill cancer cells or tumors. It can be used alongside surgery.
• Targeted therapy is the term for medications that work by disrupting how cancer cells multiply and spread. It may be used in combination with other therapies, or for patients whose tumor returns after other types of treatment.

Who Treats Gliomas?

Gliomas are a type of brain tumor that can affect both adults and children. Patients with glioma receive care from a multidisciplinary cancer care team that may include:

• Neuro-oncologists who specialize in cancers that affect the brain and central nervous system.
• Neurosurgeons, who are surgeons with expertise in removing tumors from the brain and spinal cord.
• Medical oncologists with experience using medications such as chemotherapy, immunotherapy and targeted therapies to treat cancer.
• Pathologists, who help diagnose glioma using tissue and tumor samples.
• Radiation oncologists, who are specialists in using radiation therapy to target and destroy cancer cells.
• Specialized pharmacies, which offer access to medications for hard-to-treat conditions.
• Supportive medicine providers, who help patients manage the physical, emotional and social side effects of cancer and its treatments.

Glioma Survival Rate

The survival rates for glioma vary based on a wide range of factors, including what type and grade of glioma a patient has, where their tumor is located and their age, health and choices related to care. Generally speaking, lower-grade gliomas have a higher survival rate than higher-grade gliomas.

Learn more about astrocytoma survival rates

Learn more about glioblastoma survival rates