About Oligodendroglioma

What is Oligodendroglioma?

Oligodendroglioma [ah-lih-goh-DEN-droh-glee-OH-muh] is a rare type of tumor that starts in the brain or, less often, in the spinal cord. It begins in cells called oligodendrocytes, which normally help protect nerve fibers and support nerve signaling. Most oligodendrogliomas form in the main part of the brain, especially the frontal or temporal lobes.

Oligodendrogliomas are grouped as grade 2 or grade 3 tumors. Grade 2 tumors usually grow more slowly. Grade 3 tumors, sometimes called anaplastic oligodendrogliomas, grow more quickly and usually need more intensive treatment. Symptoms often depend on the tumor’s size and location and may include seizures, headaches, changes in thinking or memory, weakness, numbness, speech problems, or changes in behavior.

Doctors confirm the diagnosis by testing tumor tissue. A diagnosis of oligodendroglioma requires two specific tumor changes: an IDH gene mutation and a combined loss of parts of chromosomes 1 and 19, called 1p/19q codeletion. These changes help doctors confirm the tumor type and plan treatment.

Oligodendroglioma Causes and Risk Factors

The exact cause of most oligodendrogliomas is not known. These tumors happen when cells develop changes in their DNA that affect how the cells grow and divide. These DNA changes are usually found only in the tumor cells and are not inherited.

Known or possible risk factors include:

• Previous exposure to radiation to the head or brain
• Certain inherited genetic conditions or inherited gene changes, which may increase the risk of some brain tumors

Most people who develop oligodendroglioma do not have a clear risk factor. Having a risk factor does not mean someone will develop this tumor, and not having a risk factor does not mean someone cannot develop it. If you have symptoms or concerns about your risk, talk with a healthcare professional.

Oligodendroglioma Symptoms

Symptoms of oligodendroglioma depend on where the tumor is, how large it is, and how quickly it is growing. Seizures are often the first symptom. Other symptoms may include:

• Headaches
• Problems with thinking, memory, or concentration
• Weakness or numbness, often on one side of the body
• Speech or language problems
• Changes in behavior, personality, balance, or movement

As the tumor grows or affects different parts of the brain, symptoms may change or become more noticeable. Possible symptoms include:

• New or worsening weakness, numbness, or trouble moving part of the body
• Changes in behavior, mood, or personality
• Memory problems or confusion
• Vision, hearing, speech, or language changes
• Problems with balance, coordination, reading, or writing
• More frequent or more severe seizures

These symptoms can also be caused by conditions other than oligodendroglioma. If you have a new seizure, sudden weakness, trouble speaking, severe or worsening headache, or other new neurological symptoms, seek medical care promptly.

How is Oligodendroglioma Diagnosed?

Doctors use several steps to diagnose oligodendroglioma and understand how it may behave:

• Neurological exam: A healthcare professional checks vision, hearing, balance, coordination, strength, reflexes, memory, and thinking. This helps identify which part of the brain or spinal cord may be affected.
• Imaging tests: MRI is usually the main imaging test used to look for a brain tumor and understand its size and location. CT scans may be used in some situations, such as when MRI is not available or when doctors need to look for calcium deposits in the tumor.
• Tissue testing: When possible, doctors remove a tumor sample during surgery or biopsy. A specialist examines the tissue under a microscope and tests it for changes such as an IDH mutation and 1p/19q codeletion.

To understand the tumor grade and help plan treatment, doctors may recommend:

• Additional imaging: Specialized MRI techniques may help doctors plan surgery or better understand the tumor’s activity and relationship to important brain functions.
• Surgery or biopsy: Removing tissue is usually needed to confirm the diagnosis. The results help doctors distinguish oligodendroglioma from other brain tumors and decide which treatments may be most useful.
• Lab tests: Blood tests do not diagnose oligodendroglioma, but they may be used to check overall health before surgery or other treatments.

Your healthcare team will explain which tests are needed based on your symptoms, imaging results, tumor location, and overall health.

Oligodendroglioma Treatment Options

Treatment for oligodendroglioma depends on the tumor grade, location, symptoms, test results, how much tumor can be safely removed, and a person’s overall health. The goals of treatment are to:

• Confirm the tumor type with tissue and molecular testing
• Remove as much of the tumor as safely possible
• Control symptoms and lower the chance that the tumor will grow or come back

Treatment options may include:

• Surgery: Surgery is often the first treatment when it can be done safely. It can remove tumor tissue, reduce pressure or symptoms, and provide tissue needed for diagnosis.
• Radiation therapy: Radiation uses high-energy beams to damage tumor cells. It may be used after surgery, especially for higher-grade tumors, tumors that cannot be fully removed, or tumors that are more likely to grow again.
• Chemotherapy: Chemotherapy uses medicines to slow or kill tumor cells. Common options may include a combination called PCV or a medicine called temozolomide, depending on the person’s situation and the healthcare team’s recommendation.
• Clinical trials: Clinical trials test new ways to diagnose, monitor, or treat tumors. Joining a clinical trial may be an option for some people and should be discussed with the healthcare team.
• Symptom management and follow-up care: Medicines and supportive care may help manage seizures, headaches, swelling, fatigue, mood changes, or rehabilitation needs. Regular follow-up imaging is often needed because oligodendrogliomas can grow or come back over time.
• Observation in selected cases: Some slow-growing grade 2 tumors may be monitored closely after surgery before starting radiation or chemotherapy, depending on symptoms, remaining tumor, and other risk factors.

Your healthcare team will recommend a plan based on your diagnosis and personal circumstances. Ask what grade the tumor is, whether it has an IDH mutation and 1p/19q codeletion, what treatment options are available, and what follow-up schedule is recommended.

Each treatment can have benefits and risks. Talk with your healthcare team about possible side effects, how treatment may affect daily life, and when to call for urgent medical advice.