A meningioma is a tumor that begins in the membranes that surround your central nervous system (CNS) (your brain and spinal cord).

A meningioma isn’t technically a brain tumor. Because it may affect your brain by pushing on it, it’s often included in this category.

Meningiomas usually grow very slowly. It sometimes can take years before they become apparent. Because of that, they may not cause any symptoms. Doctors sometimes discover a meningioma on a head MRI ordered for a different reason. However, large meningiomas may cause symptoms.

In this article, we take a closer look at meningiomas, including their causes and diagnosis and the treatment and outlook for people with meningiomas.

Your brain and spinal cord are protected and supported by three membrane-like layers, called meninges. Meningioma typically begins in the cells of the middle layer, called the arachnoid cap cells.

A meningioma can affect any part of your CNS, but it’s most common in your brain, specifically in the cerebrum and cerebellum.

Doctors group meningiomas based on how quickly they grow. This is called grading. Low-grade meningiomas are slow-growing, while high-grade meningiomas are fast-growing. There are a total of three grades:

  • Grade 1 (benign or typical) is the slowest-growing, noncancerous type of meningioma.
  • Grade 2 (atypical) is neither benign nor malignant (cancerous) but may become malignant at some point.
  • Grade 3 (malignant or anaplastic) is the most aggressive type of meningioma.

Researchers estimate that approximately 81% of meningiomas are grade 1, 17% are grade 2, and 2% are grade 3.

Illustration showing where meningiomas develop in the brain Share on Pinterest
Where meningiomas develop in the brain and spinal cord. Illustration by Wenzdai Figueroa

A meningioma is the most common tumor of the CNS, accounting for approximately 38% of all CNS tumors. It’s also the most common benign (noncancerous) tumor.

Meningiomas are more common in women, but aggressive types of meningioma are more prevalent in men. Black people are at the most risk of meningioma, followed by white people and Asian-Pacific Islanders. The risk of developing meningioma increases with age.

The causes of meningioma aren’t known. Most meningiomas are sporadic and occur without a known cause, but some can be inherited. The inherited forms of meningioma occur due to certain genetic mutations.

The following risk factors can increase your chances of developing a meningioma:

Often, meningiomas don’t cause any symptoms or signs. However, if a meningioma is large, it can press on your brain or spinal cord, causing the following symptoms:

Be sure to tell a doctor if you experience any of these symptoms.

It can be difficult to diagnose meningiomas because they often don’t have any symptoms. In addition, meningioma symptoms can be confused with other brain conditions. Because of that, meningiomas can sometimes be misdiagnosed, and it can take a few years to reach the correct diagnosis.

If your doctor suspects a meningioma, they’ll perform a few tests to confirm the diagnosis:

Treatment of meningioma depends on several factors:

  • your age and overall health
  • whether your meningioma is slow- or fast-growing
  • tumor location

The following treatment options are available to people with meningioma:

  • Active surveillance, also known as watch-and-wait: This option is only appropriate for grade 1 (slow-growing) meningiomas. During active surveillance, the tumor is monitored and treatment begins if it starts growing or causing any symptoms or problems.
  • Surgery to remove the tumor: Surgery is the most common treatment approach for meningioma and often the only treatment you might need.
  • Radiation therapy: Radiation therapy is usually used in combination with surgery for the most aggressive tumors or when surgery can’t be performed. Sometimes very small tumors can be treated with just focused radiation.

After your treatment finishes, you’ll have regular follow-up appointments with a doctor or nurse. How often you’ll have these checkups will depend on your tumor specifics.

Your outlook if you have a meningioma depends on your age and the type of treatment you have. Younger patients usually have better outcomes. Surgery that’s able to remove the entire tumor is associated with a better outlook.

According to the Central Brain Tumor Registry of the United States statistical report, the overall 10-year survival rate for benign meningioma of 84%. This means that 84% of people with noncancerous meningiomas are expected to live at least 10 years after their diagnosis.

The 10-year survival rate of malignant meningiomas is 62%. Both benign and malignant spinal cord meningiomas have a better survival rate than the same grades of brain meningiomas.

However, your individual situation might be different. Be sure to talk with a doctor about your individual outlook.

A meningioma is a tumor that begins in the membranes that surround your brain and spinal cord. It most commonly affects your brain, specifically, the cerebrum and cerebellum. Most meningiomas are benign and slow-growing.

Although the exact causes of meningioma aren’t known, it can sometimes be genetic. Other risk factors include radiation exposure, certain medical conditions, and high BMI.

Diagnosis of meningiomas can be challenging because they often don’t cause any symptoms. Treatment usually involves surgery and sometimes radiation therapy. Most meningiomas have relatively high survival rates.