Meningioma: A Plain-Language Guide

This page is for people who have been told they have a meningioma, and their families. It covers grades, symptoms, causes, treatment, and outlook.

A meningioma is a primary central nervous system tumor. That means it begins in the brain or spinal cord. It has not spread there from somewhere else.

According to NCI, these tumors form along the dura mater. That is the outermost of the three layers of the meninges, the covering that protects the brain and spinal cord. They grow from meningeal cells. So they tend to occur along the surface of the brain, rather than deep inside it.

NCI states that meningiomas are the most common type of primary brain tumor overall. NCI's PDQ summary on central nervous system tumors puts numbers on that. The PDQ summary says meningiomas make up 27% of primary brain tumors.

NCI also notes that higher grade meningiomas are very rare.

Grading comes from tissue, not from a scan. NCI says an accurate diagnosis needs tumor tissue, removed during surgery where possible. A neuropathologist, a doctor who specializes in diagnosing nervous system tissue, then reviews it.

Grade 1 meningiomas are the most common. NCI calls them low grade tumors, meaning the cells grow slowly.

Grade 2, called atypical, are mid-grade. The practical difference, NCI says, is that they have a higher chance of coming back after they have been removed. Named subtypes are chordoid and clear cell meningiomas.

Grade 3, called anaplastic, are malignant and fast-growing. Named subtypes are papillary and rhabdoid meningiomas.

NCI's PDQ summary on CNS (central nervous system) tumors says WHO grade I meningiomas have low proliferative potential, are often discrete, and may be cured by surgery alone. For grade I tumors found by chance that cause no symptoms, the PDQ says active surveillance with deferred treatment is an option, as is surgery.

NCI describes three patterns of spread, which line up with the grades:

• Meningiomas can spread to other areas of the central nervous system through cerebrospinal fluid, the fluid around the brain and spinal cord.
• Grade 2 meningiomas can invade surrounding tissue, including nearby bone.
• Grade 3 meningiomas have irregular cells. NCI says they are likely to invade the brain, or spread to other organs in the body.

Ask your team how the grade affects your follow-up scans and treatment plan.

NCI describes the typical appearance of grade 2 and grade 3 meningiomas on MRI. They usually appear as an enhancing mass on the outside lining of the brain tissue, which may or may not brighten with contrast (a dye used during the scan).

This means contrast is not a reliable way to tell grade. That is another reason the neuropathologist's reading of tissue carries the decision.

NCI lists these possible symptoms of meningioma. Ask your team how they relate to where your tumor sits:

• Vision changes
• Loss of hearing or smell
• Confusion
• Seizures
• Headaches that are worse in the morning

Tell your team about any new headaches, seizures, or changes in vision, hearing, or thinking. If someone has a seizure, or sudden confusion or weakness, call 911 or your local emergency number.

NCI's picture of who gets meningioma is clear, and it flips between grades.

Grade 1 meningiomas are more common in females. Grades 2 and 3 occur more often in males.

High-grade meningiomas are most common in non-Hispanic white people. They tend to occur in people around 60 years old, and risk rises with age.

NCI estimates that 3,360 people are living with high-grade meningiomas in the United States, as of December 31, 2019.

NCI states plainly that the cause of meningiomas is not known.

It then names two things that raise risk. Exposure to radiation, especially in childhood, can increase a person's risk of developing a meningioma. And people with the genetic condition neurofibromatosis type 2 are at increased risk.

That radiation link is well documented. NCI's PDQ summary on late effects of childhood cancer treatment lists meningioma among the new tumors that can develop in childhood cancer survivors. It reports a 30-year cumulative incidence of 3.1%, meaning 3.1% of survivors had one within 30 years.

For a malignant meningioma, NCI says the first treatment is surgery, if possible.

The surgery has two goals:

• Obtain tissue to determine the tumor type.
• Remove as much tumor as possible without causing more symptoms.

The second goal means surgeons weigh how much tumor to remove against the risk of new symptoms.

Most people with atypical and anaplastic meningiomas get more treatment after surgery. NCI names radiation, chemotherapy, or clinical trials. It says trials test new chemotherapy, targeted therapy, or immunotherapy drugs.

NCI says treatment choices depend on four things:

• The patient's age
• How much tumor remains after surgery
• The tumor type
• The tumor location

NCI publishes one number here. The relative five-year survival rate for high-grade meningioma is 63.5 percent.

That figure covers grades 2 and 3 only, which are very rare compared with grade 1. It is not the number for the common form of this tumor.

NCI also lists what shifts the outlook (prognosis) away from any average:

• Tumor grade
• Location
• Tumor type
• Extent of spread
• Genetic findings
• The person's age
• How much tumor remains after surgery, where surgery is possible
• Response to treatment

NCI does not publish a follow-up scan schedule or a separate survival figure for grade 1 disease on this page. Both are questions for the treating team.

The wider category is described in brain tumors, with the range of diagnoses in brain tumor types. The symptom question people most often arrive with is handled in is a headache a sign of a brain tumor.

• NCI: meningioma diagnosis and treatment
• NCI PDQ: CNS tumors, HP version
• NCI PDQ: late effects, HP version