What Is Meningioma?

A meningioma is a tumor that originates in the meninges. The meninges are the three outer layers of tissue that protect the central nervous system, including the brain and the spinal cord. The three layers are called:

1. Dura mater
2. Arachnoid mater
3. Pia mater

Meningiomas grow out of the middle layer, or tissues, called the arachnoid.

Meningiomas are the most common type of brain tumor. They comprise around 30% of all brain tumors. Most meningiomas (around 80%) are noncancerous, also called benign. But “benign” meningiomas can still be life-threatening. They can grow large enough to harm the nerves and brain and cause severe, permanent or fatal complications.

According to the Cleveland Clinic, around 170,000 people are diagnosed with meningioma annually in the United States. These tumors are more common in adults than children, with the average age of diagnosis at 66 years.

Women are more likely to develop meningiomas than men. Researchers think this may be because of certain hormones in female bodies. However, men are more likely to have cancerous (malignant) meningiomas. In addition, black people have a higher rate of meningioma than other ethnic groups in the U.S.

Healthcare providers use tumor tissue analysis to grade meningiomas based on their characteristics. The grading system they use is the World Health Organization (WHO) classification of brain tumors.

Grades of meningiomas include:

• Grade I (typical): This is a benign, slow-growing meningioma. Around 80% of meningiomas are typical.
• Grade II (atypical): Grade II meningiomas are also benign. They grow faster than Grade I tumors and can be more treatment-resistant. Atypical meningiomas account for around 17% of all meningiomas.
• Grade III (anaplastic): Grade III meningiomas are cancerous. These tumors grow and spread quickly. Around 1.7% of meningiomas are anaplastic.

Doctors also classify meningiomas by their location and tissue type. Examples include:

• Convexity meningioma: These tumors grow on the surface of the brain directly under the skull. They may be asymptomatic until they grow large enough to push on the brain. About 20% of meningiomas are convexity meningiomas.
• Falcine and parasagittal meningioma: This brain tumor forms in or beside the falx. The falx is a thin layer of tissue between the two sides of the brain.
• Intraventricular meningioma: These tumors grow in the ventricular system in the brain that makes and distributes cerebrospinal fluid (CSF). They can block the flow of CFS, resulting in hydrocephalus (a potentially severe or fatal build-up of fluid in the brain).
• Olfactory groove meningioma: This type forms along the nerves that run between the brain and the nose. They account for around 10% of all meningiomas. These tumors can cause a loss of smell and grow big enough to cause vision problems.
• Posterior fossa / petrous meningioma: These tumors account for another 10% of all meningiomas. They grow along the underside of the brain and can press on the cranial nerves. The pressure can cause facial and hearing problems. Petrous meningiomas can push on the trigeminal nerve (a large nerve on each side of our face). This pushing can lead to a condition called trigeminal neuralgia that causes severe facial pain.
• Skull base meningioma: These meningiomas develop in the bones that form the bottom of the skull and in the bony ridge behind the eyes.
• Sphenoid wing meningioma: These meningiomas grow on the skull base between the eyes. Around 20% of meningiomas are this type.
• Suprasellar meningioma: These tumors develop at the base of the skull near the optic nerve and pituitary gland. They can cause visual problems and pituitary gland dysfunction.

Any meningioma that comes back after treatment is called a recurrent meningioma. Recurrent meningiomas may return as the same grade or in a more aggressive or malignant form.

The WHO examined meningioma cells microscopically and identified 15 meningioma variations. These meningioma subtypes show the differences in tumor growth rate and likelihood of recurrence.

Meningioma tumors usually grow slowly. Several years could pass before a meningioma is large enough to cause symptoms. Symptoms often develop gradually.

Symptoms of a meningioma vary based on where the tumor develops and how big it is. Common side effects of a meningioma brain tumor may include:

• Behavioral or personality changes
• Changes in vision, including blurred vision, double vision or loss of vision
• Dizziness
• Headaches
• Hearing loss
• Memory problems
• Muscle weakness
• Nausea and vomiting
• Overactive or over-responsive reflexes (hyperreflexia)
• Paralysis
• Seizures

Meningiomas can also grow on the spine, though spinal meningiomas are rare. Symptoms of this type of tumor include:

• Neurological problems, like decreased or absent reflex responses (hyporeflexia), poor muscle tone and weakness
• Pain at the tumor location
• Radiculopathy (pain, numbness and tingling along a pinched nerve in the back)

You should see a doctor if you frequently experience mild meningioma symptoms, like headaches or dizziness. In addition, contact your doctor if symptoms become more severe. More serious side effects, like the sudden onset of seizures, may require emergency medical attention.

It is important to understand that not all meningiomas are discovered because patients have symptoms. Instead, doctors find them when scanning patients for other medical reasons.

Doctors do not know the exact cause of meningiomas, but the medical community has identified some risk factors.

A genetic condition called neurofibromatosis type 2 (NF2) increases risk for developing meningiomas. NF2 causes tumor growth on the nerves of the inner ear.

Doctors have identified a link between benign meningiomas and exposure to female sex hormones. Non-cancerous meningioma is twice as likely to emerge in people who were gender-assigned female at birth (AFAB) as people gender-assigned male at birth (AMAB). Risks can increase because of using hormone replacement therapy, birth control or having breast cancer.

The possible link between meningioma and Depo-Provera®

A 2024 study published by the British Medical Journal (BMJ) has found a link between meningioma and the use of Depo-Provera for birth control. 
Researchers linked an increased risk of developing intracranial meningiomas with using injectable medroxyprogesterone acetate for a year or more. This drug is the generic name for the hormone in Depo-Provera. Depo-Provera is a birth control shot (injectable contraceptive). Doctors give patients the shot every three months (13) weeks.

There are many birth control risks related to various forms of contraception. These risks have resulted in several birth control lawsuits, including lawsuits over Depo-Provera.

Depo-Provera lawsuits against manufacturer Pfizer are being filed by women who have developed dangerous meningioma brain tumors. If you took this form of birth control and have been diagnosed with a meningioma, you may qualify to take legal action.

Meningioma treatment options will vary depending on the size and location of the tumor, its growth rate and whether it’s cancerous or noncancerous. Doctors will also consider a patient's goals and overall health when deciding on the best meningioma therapy.

Healthcare providers may take a “wait and see” approach with noncancerous meningiomas. When a tumor is small and slow-growing, doctors may choose not to offer immediate treatment. Instead, they monitor the growth of the tumor and screen patients for side effects until they need medical intervention.

When treatment is needed, the first option is usually surgery to remove the meningioma. People with atypical and anaplastic meningiomas (Grades II and III) often need more treatment after surgery. They may have radiation therapy and chemotherapy. They may also enter clinical trials to test new chemotherapies, targeted therapies and drug therapies.

Meningioma prognosis

The prognosis for meningioma is different based on the grade of the tumor.

Benign meningioma life expectancy is relatively high. People with Grade I tumors have a 95.7% survival rate after five years and a 90% survival rate after 10 years. People with faster-growing but still benign Grade II tumors have an 81.8% five-year survival rate and a 69% 10-year survival rate.

People with cancerous Grade III meningioma tumors have a 46.7% survival rate after five years. The 10-year survival rate has been increasing thanks to new treatments.

For decades, Motley Rice has fought for justice for individuals, families and consumers. Our attorneys have taken leadership roles in landmark legal actions against pharmaceutical companies and manufacturers who have harmed the public with dangerous drugs, medical devices and products.

We are well-versed in women’s health litigation, including cases involving birth control, breast implants, transvaginal mesh, talcum powder and hair relaxers.

If you or someone you love developed a meningioma after using Depo-Provera, we can advise you of your legal options. You may be eligible to seek compensation for your illness and related financial damages. Contact our medical birth control lawyers or call 800.768.4026 to learn more about Depo-Provera lawsuits and your rights.

Read more on our medical drug litigation experience.

Do not stop taking prescribed medication without first consulting with your doctor. Discontinuing prescribed medication without your doctor’s advice can result in injury or death. Depo-Provera remains approved by the U.S. Food and Drug Administration.