Meningiomas are the most common type of primary brain tumor. They develop in the meninges, the layer of tissue that covers the brain. Thus, technically, meningiomas don’t originate from the brain itself but can grow into the brain, pushing and deforming it.

Most meningiomas are benign and slow-growing. This means that they don’t necessarily pose an immediate danger to patients. Some meningiomas can even be watched for years without active treatment. However, benign meningiomas can still cause problems and interfere with a patient’s quality of life.

Surgery is the most common form of treatment for meningiomas, although small tumors can sometimes be monitored for years without intervention.

As part of the Restorative Skull Base Program in the Brain Tumor Center at Siteman Cancer Center, our Washington University surgeons excel at removing meningiomas using open and minimally invasive techniques, both of which yield excellent neurological and cosmetic results.

What are the symptoms of a meningioma?

Meningiomas don’t always cause symptoms. Many patients learn that they have one only after undergoing imaging for an unrelated reason.

When meningiomas do cause symptoms, it’s because the tumor mass is pushing the tissues of the brain. Symptoms vary according to where the meningioma is located. Common symptoms include:

  • Headaches, which may be more severe in the morning
  • Impaired vision
  • Hearing loss
  • Forgetfulness
  • Weakness
  • Seizures
  • Problems producing or understanding speech

What are the risk factors for a meningioma?

Anyone can develop a meningioma, although certain individuals are more at risk than others. Keeping in mind that meningiomas are still very rare in the general population, you may be somewhat more likely to have one if you:

  • Previously received radiation therapy to the head
  • Have been diagnosed with the genetic disorder neurofibromatosis 2
  • Are a woman of older age

How are meningiomas treated?

It’s not always necessary to undergo treatment for a meningioma. Depending on the size and location of your tumor, and whether it is causing symptoms, your care team might decide to just watch the meningioma instead (conservative management or surveillance). You’ll meet with your physicians regularly and undergo MRIs to make sure the tumor isn’t growing.

If the meningioma does require treatment, most patients undergo surgery to remove it. Some patients are also given radiation therapy instead of, or in addition to, surgery.

Surgery for meningiomas

To reach a meningioma, it’s necessary for surgeons to open the skull, a procedure known as a “craniotomy.” Once they have access to the meningioma, the surgical team will use precise instruments, including neuronavigation (“GPS” for the brain) and an operating microscope, to safely remove it. They may also use intraoperative magnetic resonance imaging (or iMRI) to track their progress and make adjustments as they work.

The Washington University surgeons at Siteman are experts at removing meningiomas using what’s known as a “keyhole” technique, in which the procedure is conducted through a small hole drilled in the skull. This means that patients are spared some of the risks associated with a larger incision and more extensive tissue dissection.

Learn more about surgery for brain tumors.

Radiation therapy for meningiomas

Siteman Cancer Center offers several types of advanced radiation therapy that can achieve excellent results in meningioma patients.

  • Gamma Knife: Gamma Knife stereotactic radiosurgery is a form of radiation therapy that can replace surgery in certain cases. It delivers a highly concentrated dose of radiation to the tumor while leaving the surrounding areas intact. Often completed in a single session, the Gamma Knife procedure causes cell death in tumor cells.
  • Proton beam radiation therapy: During proton beam therapy, the tumor is hit with a single stream of protons. Unlike other forms of radiation therapy, the proton beam can be adjusted to stop at a specific depth, which means that it won’t disturb any of the tissues beyond the tumor site. Siteman was the first institution in the region to offer proton beam technology.

These techniques deliver highly concentrated doses of radiation to specific targets, making them ideal for individuals with these tumors.

Learn more about radiation therapy for brain tumors.

Clinical trials for meningiomas

Meningiomas can be a treatable form of brain tumor, but Washington University physicians and scientists are still working towards better approaches. At Siteman, we are: