Oligodendroglioma tumors

About 60% of people who are diagnosed with an oligodendroglioma brain tumor have a seizure before their diagnosis. That can be a startling introduction to the world of primary brain tumors. You can count on us to use the latest tools for accurate diagnosis.

What is an oligodendroglioma?

An oligodendroglioma tumor is a primary brain tumor that usually occurs in the frontal lobe (front) or temporal lobe (sides) of the brain. When viewed under a microscope, the cells of these tumors resemble a normal type of brain cell called an oligodendrocyte.

Research shows that these tumors don’t start out as oligodendrocyte cells. But it’s unclear what kind of cells they grow from. We do know that they grow in a general type of cells called glial cells, so oligodendroglioma tumors fit into the category of glioma tumors.

Research also shows that oligodendroglioma tumors grow in different cells in adults than they do in children. They’re the third most common primary brain tumor in adults but they’re rare in children.

Oligodendroglial tumors of the brain are slightly more common in males than in females and more common in White people and non-Hispanic people.

Types of oligodendroglioma tumors

Oligodendroglioma tumors are classified as two types. These types are determined based on the appearance of the cells and on biomarker testing of the genes inside the cells. The two types are:

• Grade 2 tumors: Slow-growing, may invade nearby normal tissue and may have no symptoms.
• Grade 3 tumors: Malignant (cancerous) and fast-growing.

Your doctor may use different terms to describe your tumor. Trust them to have the most up-to-date descriptions and information. They’re your best source and they can tell you how the size, location and any biomarkers found in your oligodendroglioma tumor are likely to affect you and your treatment.

One term that has been associated with oligodendrogliomas is anaplastic oligodendroglioma. Many experts no longer use anaplastic when describing oligodendrogliomas.

Oligodendroglioma symptoms

Slow-growing oligodendroglial tumors of the brain sometimes don’t cause any symptoms for a long time. If a grade 2 tumor turns into a grade 3 tumor, it will start to grow quickly and is more likely to cause symptoms.

The first symptom of a grade 3 tumor is often a seizure, which happens before diagnosis for many people. Other potential oligodendroglioma symptoms include:

• Balance and movement problems
• Headaches
• Numbness and tingling
• Problems with thinking and memory
• Weakness

Oligodendroglioma symptoms are different for each person. They depend on the size and location of the tumor. When a tumor grows big enough to put pressure on a part of the brain, it affects functions governed by that part of the brain.

Oligodendroglioma tumors usually don’t spread beyond the brain.

Oligodendroglioma diagnosis

Your primary care doctor is likely to refer you to an experienced neurosurgeon or neuro-oncologist if they discover you have a brain tumor. Brain tumor treatment is complex and constantly changing because of ongoing research, and you’ll get the best care from experts in the field.

Your Aurora Health Care doctor will ask about the duration and nature of your symptoms, take your medical history, and perform a physical that includes tests to find neurological signs of problems related to your symptoms. They’ll order imaging tests like an MRI or CT which provide a picture of the size and location of your tumor.

Oligodendroglioma treatment

Brain surgery (craniotomy) is often the first oligodendroglioma treatment you’ll receive. There are two goals for oligodendroglioma brain tumor surgery:

• Remove as much of the tumor as possible
• Gather tissue for a biopsy

A neuropathologist will examine biopsied tissue under a microscope to help verify the tumor type and grade. Part of the tissue will be used for biomarker testing to check for mutations or other changes in the genes inside the cancer oligodendroglioma cells. The biomarker testing looks for details about the cancer cells, including:

• Missing parts from specific chromosomes in cells of the tumor – known as 1p/19q codeletion
• Isocitrate dehydrogenase (IDH) mutation – IDH is an enzyme found in cells

Combining the IDH mutation, chromosome changes and the appearance of the cells confirms the oligodendroglioma diagnosis. Identifying ways that cancer cells are different from normal cells also helps your health care team choose medications and treatments that are most likely to work for your individual cancer.

After the tumor type and grade has been determined, your doctor will make recommendations for your oligodendroglioma treatment based on:

• How much tumor remains
• The tumor’s type and location
• Your age and general health

If the results of your surgery and testing indicate the tumor is likely to come back or if the entire tumor wasn’t removed, your doctor may recommend radiation therapy or chemotherapy. They may also recommend targeted therapy, immunotherapy or participation in clinical trials.

Medications for symptoms & side effects

Medications may be recommended to treat some symptoms or side effects from treatment.

• Seizures: When seizures continue after surgery, anti-seizure medication may be prescribed.
• Side effects from treatments: Treatments for cancer sometimes cause side effects like nausea, fatigue or depression. Medications may be prescribed for these side effects.
• Swelling near the residual tumor: Steroids may be prescribed to reduce swelling.

Monitoring and follow-up

After treatments end, you’ll be scheduled for regular monitoring. MRI scans will be taken and examined to check for growth in any remaining tumor or any new oligodendroglial tumors of the brain. Your doctor will ask about any returning symptoms, continuing side effects and how any medications you’re taking are working – particularly anti-seizure medications.