Oligodendroglioma is a rare type of brain tumor. It’s in a category of brain and spinal cord tumors called gliomas. These are brain or spinal cord tumors that come from abnormal glial cells, the supportive cells of your brain and spinal cord.
The types of abnormal cells that form oligodendroglioma are called oligodendrocytes. They surround your brain and spinal cord. When they’re normal, they support your nerve fibers located there.
Oligodendroglioma is a primary brain tumor. That means it starts in your brain. Most commonly, they happen in the frontal lobe of your brain. Secondary brain cancers are more common than primary ones. Those are cancers that start in other parts of your body, such as your breasts or lungs, and spread to your brain.
“There are approximately 1,100 new cases diagnosed in the U.S. annually,” says Morana Vojnic, MD, director of neuro-oncology at Rutgers Cancer Institute.
Most of these cases are adults. Children and infants can also get oligodendroglioma, but it’s even more rare.
What Are Grades of Oligodendrogliomas?
Doctors classify tumors based on how aggressive (fast-growing) they are. The way doctors decide your oligodendroglioma grade is by looking at cells from the tumor under a microscope.
There are two grades of oligodendrogliomas: grade 2 and grade 3.
Oligodendroglioma grade 2 (low-grade oligodendroglioma)
These tumors grow slowly and often don’t spread quickly. They may go into nearby tissue, but they don’t spread far. You may have this type of oligodendroglioma for years before it causes any symptoms. Grade 2 oligodendroglioma can become grade 3.
Oligodendroglioma grade 3 (anaplastic oligodendroglioma)
These are more aggressive, grow faster, and are malignant (cancerous). Doctors use the term anaplastic for cancer cells that divide rapidly and don’t look much like normal cells.
What Are Symptoms of Oligodendroglioma?
The symptoms you have from your oligodendroglioma depend on where the tumor is and how big it is.
The most common first sign that you have an oligodendroglioma is a seizure. Oligodendrogliomas often affect your cerebral cortex, which is the outer surface of your brain. It controls things like vision, language and muscle control. About 60% of people with oligodendrogliomas have seizures.
Other common symptoms include:
- Headaches
- Problems with thinking and memory
- Weakness, especially in muscles on one side of the face
- Numbness
- Problems with balance and movement
- Vision problems such as blurred vision, double vision, or vision loss
- Hearing loss
- Trouble speaking or understanding speech (aphasia)
Doctors call these symptoms focal symptoms because they come from focused parts of your brain.
What Causes Oligodendrogliomas?
Experts don’t know the exact reason people get oligodendroglioma, but they know that genes may play a part.
“In fact, we use specific genetic markers in the tumor — IDH mutation and a combined loss of chromosome 1p and 19q — to make an oligodendroglioma diagnosis,” says Vojnic.
Most cases of oligodendroglioma are sporadic, which means they don’t have a clear genetic or environmental reason for happening.
Are there risk factors for oligodendroglioma?
If you have a family history of brain tumors or certain hereditary syndromes such as Li-Fraumeni syndrome, Turcot syndrome, or NF1, your chances of getting oligodendroglioma are slightly higher than someone who doesn’t have these factors. Radiation exposure, like you would get because of past cancer treatment, may slightly increase your risk, but it's rare.
You’re more likely to get a diagnosis between ages 30-50. You’re slightly more at risk of getting oligodendroglioma if you’re male.
How Is Oligodendroglioma Diagnosed?
When a doctor is trying to figure out if you have oligodendroglioma, there are several steps they take. They’ll do a physical exam and go over your medical and family history. They’ll also do a neurological exam, which is a careful look at things like:
- Reflexes
- Cognition
- Coordination and strength
- Vision
Then they’ll use imaging scans to look inside your skull. These may include:
CT scan. CT stands for computed tomography. CT scans use X-rays, which highlight calcium inside your body. (This is why you can see bones with X-rays.) Oligodendrogliomas often have calcium in them and show up on CT scans.
MRI (magnetic resonance imaging). This is the most common tool doctors use to diagnose oligodendrogliomas. An MRI uses strong magnets and radio waves to make detailed images of your brain. Your doctor can see where the tumor is, what size it is, and other things about it, such as how it looks. Oligodendrogliomas often have a “fried egg” appearance.
Once your doctor sees that you have a tumor in your brain, they need a sample of the cells in the tumor to confirm that it’s oligodendroglioma. They may collect these cells during surgery to remove the tumor, or they may do a biopsy by itself. Once your doctor has collected the cells, they send them to a lab for testing. The lab will look at what the cells look like and also do genetic testing on them.
What Are Treatment Options for Oligodendroglioma?
The treatment that will work best on your oligodendroglioma depends on its unique features, including size, location, genetic markers, and your symptoms.
Surgery. The first step is often to remove as much of the tumor as is safely possible while keeping important brain functions working. You may have to be awake for this surgery so that doctors can see which parts of your brain are affected.
Radiation. If surgery doesn’t get all of your tumor, or if your doctor thinks it has a strong chance of coming back, you may need radiation. This treatment uses high-energy radiation to kill the cancer cells and stop them from spreading. Radiation typically takes place over six weeks and may be given along with chemotherapy.
Chemotherapy. You take chemotherapy drugs by mouth or through an IV. They kill fast-growing cells in your body, such as cancer cells. Two common forms of common chemotherapy are the PCV regimen (procarbazine, lomustine, and vincristine) or TMZ (temozolomide). TMZ often has fewer side effects.
Targeted therapy. In 2024, the FDA approved a drug called vorasidenib (Voranigo) for treating grade 2 oligodendrogliomas with an IDH1 or IDH2 mutation. Depending on your case and symptoms, this may be an option.
Sometimes doctors recommend a “watch and wait” approach to oligodendrogliomas. This is more common with small, slow-growing, low-grade tumors. You’ll get regular scans to monitor growth before you start any treatment.
Can oligodendroglioma be cured?
Right now, doctors don’t consider oligodendroglioma curable. Even when you treat the tumor, there’s a high chance it will come back.
“In general, oligodendrogliomas are treatable but not curable,” says Vojnic. “Long-term ‘remissions’ are obtainable, but the prognosis depends on the initial tumor grade, how much tumor was removed during surgery, and the type of treatment you received after surgery.”
What's the Recurrence Rate of Oligodendroglioma?
Oligodendroglioma often comes back, even if you have a low-grade case.
“Typically it doesn’t spread outside the brain and often comes back in the same area where it was initially discovered, which is why all patients with this disease are monitored with frequent brain scans,” says Vojnic.
Your doctor may recommend imaging every few months, especially in the years right after treatment. If the tumor does return, your care team will talk with you about the next best step for treatment.
What's the Prognosis With Oligodendroglioma?
Many people, especially those who have low-grade oligodendroglioma, can live for many years with a good quality of life. The five-year survival rate, which is the percentage of people still alive five years after diagnosis, is 79.5%.
It’s common to have long-term remission and live for 10 years or more after diagnosis.
“Based on some studies, more than half of grade 2 oligodendrogliomas do not come back within 10 years,” says Vojnic.
If you have a grade 3 oligodendroglioma, your prognosis may not be as favorable, but it depends on how your oligodendroglioma responds to treatment, your overall health, and your age.
Takeaways
Oligodendroglioma is a rare type of brain tumor. Doctors classify these tumors as grade 2 (slow growing) or grade 3 (faster growing and more aggressive). The most common first symptom is seizures, though headaches, memory issues, weakness, and vision changes can also happen. Treatments like surgery, radiation, chemotherapy, and targeted therapy can help manage it, but oligodendroglioma isn't considered curable because it often comes back. Many people, especially with grade 2 tumors, can live for years, sometimes more than a decade after diagnosis.
Oligodendroglioma FAQs
What's the survival rate of oligodendroglioma?
Overall, the five-year survival rate for oligodendroglioma is 79.5%. This percentage varies with grade, size, and location of your tumor.
Astrocytoma vs. oligodendroglioma: what’s the difference?
Both astrocytoma and oligodendroglioma are gliomas. The difference is the type of cell they start from. Astrocytoma tumors start in glial cells called astrocytes. Oligodendrogliomas start in glial cells called oligodendrocytes.
Oligodendroglioma vs. glioblastoma: what’s the difference?
Oligodendroglioma and glioblastoma are both gliomas, but they come from different types of glial cells. Glioblastomas are the most common form of glioma. They grow faster than oligodendrogliomas.
Who's the longest survivor of oligodendroglioma?
One 1969 case study in the Journal of Neurosurgery reported a patient still living 40 years after an oligodendroglioma diagnosis.
What's the average age at diagnosis of oligodendroglioma?
Doctors diagnose most cases of oligodendroglioma in people 30 to 50 years old.
