Meningioma
Meningiomas are one of the most common brain tumors. They are often non-cancerous, but because of their location near the brain they may need treatment.
What is a meningioma?
A meningioma is a tumor of the meninges, the thin layers of tissue that cover the brain and spinal cord. Most meningiomas are benign, or non-cancerous. But because of their location near the brain and spinal cord, these tumors can cause problems.
See Brain Tumors in Adults to learn about the parts of the brain and different types of brain tumors.
How common is meningioma? Who gets it?
Over 35,000 meningiomas are diagnosed each year in the United States. Meningiomas account for about 4 in 10 brain and spinal cord tumors in adults over 40, and about 1 in 6 tumors in adolescents and young adults.
People of any age can have a meningioma, although the risk goes up as people get older. It is much more common in adults than in children.
Women are more likely to have a meningioma than men.
Risk factors for meningiomas
In addition to older age and being female, risk factors for developing a meningioma include certain genetic factors, exposure to radiation, and other environmental factors.
Having certain gene changes (mutations) can increase a person’s risk of developing tumors. Most often these changes are inherited from a parent. People with certain family cancer syndromes have a higher risk of developing a meningioma. These include:
- Neurofibromatosis type 2 (NF2-related schwannomatosis)
- Werner syndrome
- Gorlin syndrome (nevoid basal cell carcinoma syndrome)
- Cowden syndrome
A common variant in the MLLT10 gene is also linked with an increased risk of meningiomas and some other cancers, though this is not considered a family cancer syndrome.
Some environmental risk factors are called modifiable risk factors. These are things we might be able to avoid to reduce our risk of developing a tumor. They include:
- Excess body weight
- Cigarette smoking
- Radiation exposure
- Methotrexate use (this drug is used to treat some cancers and autoimmune conditions)
If you have had radiation treatments to the head (for cancer or other reasons), it’s important to know your risk and tell your doctor if you have any new signs or symptoms so the cause can be found. The effects of lower doses of radiation from imaging tests such as x-rays or CT scans aren’t as clear, but doctors generally try to avoid unnecessary radiation from imaging tests if they aren’t needed.
Researchers are also looking at the impact of some hormones on meningiomas. Meningioma cells often have receptors for progesterone or other sex hormones (meaning they’re affected by these hormones), so doctors suspect sex hormones may have a role in meningiomas. This may help explain why these tumors are more common in females. Studies looking at whether hormones play a role in developing meningiomas have had mixed results, and doctors continue to try to learn more about this.
Signs and symptoms of meningiomas
Most meningiomas tend to grow slowly over time, and many people have no symptoms, especially early on. Up to 1 in 5 meningiomas are found incidentally (when a person has no symptoms) on an imaging test done for another reason.
If a meningioma does cause symptoms, they are most often from the tumor pressing on normal tissue nearby. Symptoms can include:
- Headaches
- Seizures
- Vision changes
- Loss of hearing or smell
- Changes in behavior or personality
- Weakness of an arm or leg
For more information, see Signs and Symptoms of Brain Tumors in Adults.
How are meningiomas diagnosed?
Doctors can often tell that a person has a meningioma based on imaging test results. But a biopsy might be needed to confirm the diagnosis, as well as to determine the grade of the meningioma.
These tests use x-rays or strong magnets to create pictures of the inside of the body, including the brain. They are often one of the first tests done if a brain tumor is suspected.
- MRI (magnetic resonance imaging): This is the preferred test for looking at most tumors in the brain. It can show the size, shape and location of the tumor. Contrast may be injected into a vein before the scan to help see details better.
- CT scan (computed tomography): This test uses x-rays to make detailed cross-sectional images of the brain. It can be done quickly and may be the first imaging test done, especially in an urgent situation like a seizure or severe symptoms.
- CT or MRI angiography: These tests can show the blood vessels surrounding the tumor and may be helpful if surgery is planned.
If a tumor is causing symptoms or a diagnosis is not clear from imaging tests, a biopsy of the tumor will often be recommended. For meningiomas, a biopsy is most often done as part of surgery to remove the entire tumor, if it is safe.
The biopsy sample will be looked at under the microscope to find out the cell type, how fast the cells appear to be growing and dividing, and whether there are signs the tumor is invading nearby healthy brain tissue.
Molecular testing will also be done to look for certain gene or protein changes in the tumor cells. Some of these changes are linked to how the tumor behaves and may help guide treatment decisions.
For more on imaging tests and biopsies that might be done, see Tests for Brain Tumors in Adults.
Meningioma grading
Doctors use a combination of how the biopsy looks under the microscope and molecular testing results to assign a grade to each meningioma.
The grade of the tumor helps doctors predict its behavior and how likely it is to come back. Meningiomas are graded on a scale from 1 to 3.
- Grade 1 tumors are benign, or non-cancerous. The cells do not appear to be growing very fast and do not have any of the features of higher-grade meningiomas. These tumors don’t invade nearby areas, although they can still cause problems if they grow large enough. Most meningiomas are grade 1.
- Grade 2 tumors grow faster than grade 1 tumors, but not as fast as grade 3 tumors. They have a high number of smaller, dividing cells or areas of cell death that suggest the tumor is growing. These tumors may spread into nearby normal tissue and are more likely to come back (recur) after surgery.
- Grade 3 tumors can grow quickly and are considered malignant or cancerous. The cells can have features of other types of cancer cells such as sarcomas. They may also have certain gene changes that make them more aggressive. These tumors can grow into nearby brain tissue and bone, and are the most likely to come back after treatment. Some may even spread to other parts of the body.
Treating meningiomas
Treatment for a meningioma depends largely on whether a person has symptoms.
Meningiomas that aren’t causing symptoms can often be watched closely with imaging tests like MRIs to see whether they grow over time, without doing a biopsy or surgery. But surgery may be done to try to remove the tumor if it is large or growing, or if the person prefers to have it removed.
Treatment for symptomatic meningiomas depends on the location of the tumor and whether it can be removed completely, the grade of the tumor, and a person’s overall health and preferences.
For people in good health, surgery is often the first step.
After surgery, the most common options are:
- Grade 1 tumors completely removed by surgery: Observe with imaging tests for any signs of the tumor coming back
- Grade 1 tumors not completely removed by surgery: Observe with imaging tests for signs of tumor growth or treat with stereotactic radiosurgery or another type of radiation therapy
- Grade 2 tumors completely removed by surgery: Observe with imaging tests or treat with radiation therapy
- Grade 2 tumors not completely removed by surgery: Treat with radiation therapy
- Grade 3 tumors: Treat with radiation therapy or take part in a clinical trial of a newer treatment.
People who are not healthy enough for surgery may be treated with radiation therapy (including SRS) instead.
The goals of surgery for meningiomas are to get a biopsy sample to confirm the diagnosis and to remove as much of the tumor as safely possible (maximally safe resection) to relieve any symptoms. Whenever possible, the goal is to remove the entire tumor, since complete removal is linked with a better outlook.
Surgery may be done through a craniotomy (a hole made in the skull to operate through) or with endoscopic surgery (using smaller surgical tools through a smaller hole), depending on the location of the tumor, the person’s health, and the surgeon’s expertise.
Often imaging tests can be used to help surgeons remove the tumor while avoiding important parts of the brain.
To learn more, see Surgery for Brain Tumors in Adults.
After surgery, if a meningioma was found to be high grade or if it wasn’t removed completely, radiation therapy may be recommended to try to kill any remaining cancer cells.
Radiation is often the main treatment if surgery can’t be done for some reason.
This is usually done 5 days a week for a few weeks.
Stereotactic radiosurgery (SRS)/Stereotactic radiotherapy (SRT)
This type of radiation therapy delivers a large, precise dose to the tumor in 1 session (SRS) or a few sessions (SRT). This technique can be used for tumors in parts of the brain or spinal cord where surgery is not possible, or if a person isn’t healthy enough for surgery.
To learn more, see Radiation Therapy for Brain Tumors in Adults.
Other treatment options show promise and may be used for aggressive meningiomas or meningiomas that come back after surgery or radiation therapy. These are mostly available through clinical trials.
Angiogenesis inhibitors: Drugs such as sunitinib and bevacizumab, which block signals that allow blood vessels to grow to feed a tumor, have been used in some hard-to-treat meningiomas.
SSTR-radioligand therapy: This treatment uses hormone-like drugs to target tumor cells with radiation. It has shown some results in meningiomas that did not respond to other treatments.
Immunotherapy: Drugs such as pembrolizumab and nivolumab, which allow the immune system to attack tumor cells, have been used in early clinical trials for people with meningiomas with some success.
After treatment for a meningioma
After treatment is complete, you will still need to see your doctor for regular follow-up exams to make sure the tumor has not come back and to check for any new symptoms or complications from the tumor and its treatment. At first, you may need more frequent follow-ups, but over time they will be needed less often.
At these visits, your doctor will ask about any new symptoms and test your strength, feeling, memory, and reflexes to see how well your brain and nervous system are working.
These visits will often include imaging tests for some time as well, to make sure the tumor has not come back.
If you have symptoms after surgery or radiation such as trouble walking, speaking, weakness, or numbness, therapy and rehabilitation may be part of your care after treatment.
If you have seizures, memory problems, or other side effects from treatment, follow-up with a neurologist (a brain specialist) may be needed.
Ask your cancer care team about what to expect after meningioma treatment.
Learn more in After Treatment for Brain Tumors in Adults.
Key points to remember
- Meningiomas are one of the most common brain tumors in adults.
- Older age, being female, and having a history of radiation treatment are some of the biggest risk factors for meningioma, but other genetic and environmental factors may play a role.
- Most meningiomas are benign (not cancer), but they can still cause problems if they grow large enough and press on other parts of the brain or spinal cord.
- Not all meningiomas cause symptoms, but if they do, symptoms depend on the location and size of the tumor.
- Doctors can often tell that a tumor is a meningioma by the way it looks on an imaging test such as an MRI or CT scan. But sometimes a biopsy is needed.
- Many meningiomas don’t need to be treated right away, especially if they’re not causing symptoms. They can be watched and then treated if they start to grow or cause problems.
- If treatment is needed, surgery is usually the first step, if it can be done. Depending on the tumor biopsy results and the person’s health, other treatments such as radiation therapy may be recommended.
- Clinical trials of new treatments such as targeted drugs and immunotherapy for meningiomas are now underway.
- Written by
- References
Developed by the American Cancer Society medical and editorial content team with medical review and contribution by the American Society of Clinical Oncology (ASCO).
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Last Revised: January 5, 2026
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