Glioma

What is Glioma?

Overview

A glioma is a type of brain tumor that develops from glial cells—specialized cells that support and protect nerve cells in the brain and spinal cord. Gliomas are the most common type of primary brain tumor, accounting for roughly 30% of all brain tumors and about 12,000 new cases each year in the United States.

Unlike many cancers, even the most aggressive gliomas rarely spread through the bloodstream or lymphatic system to other parts of the body. Instead, they typically remain confined to the central nervous system (brain and spinal cord).

Gliomas are classified by grade, which reflects how aggressive they are:

• Low-grade gliomas grow slowly and generally have a better prognosis.
• High-grade gliomas grow rapidly, are more aggressive, and often require intensive treatment.

The three main types of gliomas are:

• Astrocytomas – The most common type, arising from astrocytes.
  • The most aggressive form is glioblastoma multiforme (GBM), a high-grade tumor with a poorer prognosis. 
  • Lower-grade astrocytomas (grades 1 and 2, such as pilocytic astrocytomas) grow slowly and tend to have better outcomes.
• Ependymomas – Rare tumors that develop from ependymal cells, often found lining the brain’s ventricles or the spinal canal.
• Oligodendrogliomas – Arise from oligodendrocytes, are less common, but often respond better to treatment compared to other gliomas.

Currently, there is no cure for infiltrative or high-grade gliomas. Surgery is often performed to remove as much tumor as safely possible, followed by chemotherapy and radiation to help control growth and delay recurrence. Despite advances, microscopic tumor cells typically remain, making ongoing management essential.

Clinical trials are available for patients with both newly diagnosed and recurrent gliomas, offering access to innovative therapies such as targeted drugs, immunotherapy, and advanced surgical techniques.

Who is Affected?

Gliomas can occur in people of any age, but certain types are more common in specific age groups. Low-grade gliomas are often diagnosed in children and young adults, while high-grade gliomas, including glioblastoma, are more frequently seen in older adults. Both men and women can develop gliomas, though some studies suggest a slightly higher incidence in men. In rare cases, genetic conditions such as Li-Fraumeni syndrome or a family history of brain tumors may increase the risk.

Glioma Symptoms & Causes

Symptoms of Glioma

Glioma symptoms are variable and depend on tumor location and size.

The first symptom of a brain tumor of any type can be a headache. The reason that patients get headaches with brain tumors is that these masses cause increased pressure in the brain. The headache associated with a brain tumor is frequently worse in the morning and may be associated with nausea or vomiting.

Other common signs and symptoms of a gliomas include:

• Blurred, double or loss of vision
• Headache
• Seizures
• Confusion
• Weakness
• Numbness of a side or part of the body
• Imbalance
• In-coordination
• Memory impairment
• Changes in mood

Causes

The cause of a glioma is unknown. Although the initial cause is thought to be related to mutations in the DNA of the tumor cells, there are currently no clear-cut environmental or behavioral risk factors (such as air pollution or smoking) that are known to cause gliomas.

When to See a Doctor

Seek medical attention if you experience persistent or unexplained neurological symptoms such as headaches, seizures, vision or speech changes, weakness, loss of coordination, or personality changes. These symptoms may be caused by many conditions, but early evaluation can help identify the cause and allow for timely treatment if a brain tumor is present. If you have a known genetic risk or a family history of brain tumors, regular monitoring with a specialist may be recommended.

Glioma Diagnosis

If you experience symptoms suggestive of a brain tumor with no other clear cause, a thorough diagnostic work-up is essential.

Gliomas, like other brain tumors, are most accurately visualized using magnetic resonance imaging (MRI) of the brain, which provides detailed images of brain structures. A computerized tomography (CT) scan can also be useful, but generally offers less detail than MRI.

While MRI is highly effective at detecting a brain mass, it cannot confirm the exact type of tumor. Gliomas can appear similar to other brain tumors—or even certain infections—on imaging alone. To make a definitive diagnosis and determine the tumor’s grade, surgical removal of part or all of the tumor (biopsy or resection) is necessary.

Examining the tumor tissue under a microscope allows neuropathologists to identify the exact tumor type and assess how aggressive it is. This information is critical for guiding treatment decisions, estimating prognosis, and helping predict quality of life outcomes.

Glioma Treatment & Outcomes

Treatment Options For Glioma

The treatment of a glioma depends tremendously on the tumor WHO grade and subtype, as well as size and location of the tumor. Through many decades of research, we have learned that for most gliomas, the amount of tumor removed may correlate with survival time. At the same time, for higher grade (WHO Grade III and IV) gliomas including glioblastoma multiforme, although all visible portions of the tumor may be removed with surgery, the tumor has often already infiltrated the surrounding brain far beyond the margins of the visible tumor, making a surgical cure impossible. 

Because gliomas are infiltrative into the brain and blend into the adjacent normal brain, they typically cannot be removed completely.

Treatment for gliomas can be surgical or non-surgical.

Patient Outcomes

Outcomes for glioma vary widely depending on the tumor type, grade, location, and the patient’s overall health. Low-grade gliomas tend to grow slowly and may be managed effectively for many years, while high-grade gliomas—such as glioblastoma—are more aggressive and require intensive treatment. Advances in surgery, radiation therapy, chemotherapy, and targeted treatments have improved survival and quality of life for many patients. Participation in clinical trials may also provide access to innovative therapies that can offer additional benefits.

Managing Glioma

Living with a glioma often involves a combination of medical treatment, symptom management, and supportive care. 

• Your care plan may include surgery, radiation therapy, chemotherapy, or targeted therapies, as well as regular imaging to monitor the tumor. 
• Managing symptoms such as headaches, seizures, fatigue, or cognitive changes is an important part of maintaining quality of life. Rehabilitation services, counseling, and support groups can also play a key role in helping patients and families cope with the physical and emotional challenges of the disease. 
• Staying connected with your care team and keeping follow-up appointments ensures that any changes in your condition are addressed promptly.

Meet our Expert Specialists & Surgeons

Garni Barkhoudarian, MD

Neurosurgery

Jose Carrillo, MD

Neuro-Oncology

Adi Iyer, MD, MS

Neurosurgery, Neuro-interventional Surgery

Daniel F. Kelly, MD

Neurosurgery

Nouzhan Sehati, MD

Neurosurgery

Naveed Wagle, MD

Neuro-Oncology

Walavan Sivakumar, MD

Neurosurgery

Robert Wollman, MD

Radiation Oncology

April Vassantachart, MD

Radiation Oncology

Experience Compassionate, Expert Care

At the Pacific Brain Tumor Center at Pacific Neuroscience Institute, we incorporate leading-edge technology such as MRI fiber tractography, functional MRI, surgical navigation and awake craniotomy protocols, with proven surgical experience, to make glioma surgery safer, less invasive and more effective. 

We have a large experience in the comprehensive personalized care of all types of gliomas including astrocytomas (including glioblastomas), oligodendrogliomas, and anaplastic astrocytomas.

Our neurosurgeons work closely with our neuro-oncologists, radiation oncologists and neuropathologists to design the optimal treatment plan that incorporates the latest in radiotherapy techniques and tumor biomarker studies. 

By using comprehensive tumor histological subtyping and genomic sequencing, we are able to provide a personalized therapeutic approach for each patient. 

Our team can also facilitate participation in clinical trials using novel medical therapies for patients with gliomas.

Ashley’s Story

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