ConditionBrain & nerves
Meningioma
A meningioma is a tumor that grows from the meninges, the membranes covering the brain and spinal cord. It is the most common primary brain tumor in adults, and about 80 percent are benign (grade 1) and slow-growing. Many are found by chance on a scan and need only monitoring. Larger ones press on the brain and can cause headaches, seizures, weakness, vision or personality changes. Surgery is the main treatment, with radiation for tumors that cannot be fully removed or are higher grade.
Also called: Meningeal tumor, brain membrane tumor, benign brain tumor (most cases)
At a glance
- What it is
- A tumor of the brain or spinal cord coverings; most are benign and slow-growing.
- How common
- The most common primary brain tumor, about 4 in 10; more common in women and older adults.
- Grades
- Grade 1 (benign, about 80 percent), grade 2 (atypical), grade 3 (anaplastic, malignant).
- Symptoms
- Often none; headaches, seizures, weakness, vision, hearing, smell or personality changes.
- Diagnosis
- MRI with contrast; biopsy at surgery confirms grade.
- Treatment
- Monitoring, surgery, stereotactic radiosurgery or radiation therapy.
When to get help
Call 911 or go to the ER
- A first seizure, or a seizure lasting more than 5 minutes
- Sudden weakness, numbness, speech difficulty or vision loss
- Sudden severe headache, or headache with vomiting and drowsiness
See a doctor within a day or two
- New headaches that are worse in the morning, wake you from sleep, or worsen with coughing or bending
- Gradually increasing weakness, clumsiness or balance problems
- Personality change, confusion or memory loss noticed by family
- Gradual loss of vision, double vision, or bulging of one eye
Book a routine appointment
- A meningioma found incidentally on a scan, needing a follow-up plan
- Loss of sense of smell, or one-sided hearing loss or ringing
- Regular follow-up MRI after treatment
What meningiomas are
The meninges are three layers of tissue that protect the brain and spinal cord. Meningiomas arise from cells in the middle layer (the arachnoid). Because they grow on the surface rather than within the brain tissue, they press on the brain rather than invading it in most cases. They are usually round, well defined and attached to the dura, the tough outer layer.
Most grow slowly over years. Some never grow at all.
How common they are
Meningiomas account for about 40 percent of primary brain and spinal tumors in the US. They are about twice as common in women as men and become more common with age, especially after 60. Many are discovered on MRI or CT scans done for other reasons, such as a head injury or headaches.
Grades
The World Health Organization grades meningiomas by how the cells look and behave:
| Grade | Name | Features | Share of cases |
|---|---|---|---|
| 1 | Benign | Slow-growing, low recurrence risk after full removal | About 80 percent |
| 2 | Atypical | Faster growth, higher recurrence risk | About 15 to 20 percent |
| 3 | Anaplastic (malignant) | Aggressive, can invade brain, high recurrence | 1 to 2 percent |
Causes and risk factors
The cause of most meningiomas is unknown. Risk factors include:
- female sex, possibly linked to hormones; meningiomas can grow during pregnancy
- older age
- previous radiation to the head, including childhood radiation therapy
- neurofibromatosis type 2 and other genetic conditions
- obesity
- long-term use of some progestin medicines (such as high-dose cyproterone acetate and medroxyprogesterone) has been linked to meningioma growth
Symptoms
Symptoms depend on size and location:
| Location | Possible symptoms |
|---|---|
| Over the brain surface (convexity) | Headaches, seizures, weakness, personality change |
| Along the midline (falx, parasagittal) | Leg weakness, seizures |
| Front of the skull base (olfactory groove) | Loss of smell, personality change, vision loss |
| Around the eye (sphenoid wing) | Vision problems, eye bulging, headaches |
| Near the pituitary (tuberculum sellae) | Vision loss |
| Back of the skull (posterior fossa) | Hearing loss, facial numbness, balance problems |
| Spine | Back pain, leg weakness, numbness, bladder problems |
General symptoms include:
- headaches, often worse in the morning
- seizures
- memory problems and personality changes
- weakness or numbness in an arm or leg
- vision or hearing changes
Diagnosis
- MRI with contrast: the best test. Meningiomas show as well-defined, brightly enhancing masses attached to the dura, often with a "dural tail"
- CT scan: shows calcification and effects on the skull bone
- Biopsy or surgical removal: confirms the type and grade
- Neurological and eye exams, and hearing tests for tumors near the ear
Meningiomas need to be told apart from other tumors such as acoustic neuroma, pituitary adenoma and brain metastases.
Treatment
Active monitoring
Small meningiomas without symptoms, especially in older adults, are often monitored with MRI scans, typically after 6 to 12 months and then yearly if stable. Many never need treatment.
Surgery
Surgery is the main treatment for meningiomas that cause symptoms, are growing or are large. The goal is to remove the whole tumor and its attachment to the dura if this can be done safely. Complete removal of a grade 1 meningioma is often curative. Tumors near critical nerves and blood vessels may be only partly removed.
Radiation
- Stereotactic radiosurgery (such as Gamma Knife): a precise, high-dose single or few treatments for small tumors or remnants, controlling growth in most grade 1 tumors
- Fractionated radiation therapy: for larger tumors, those near sensitive structures, and grade 2 and 3 meningiomas after surgery
Other treatments
- anti-seizure medicines if seizures occur
- steroids to reduce brain swelling
- clinical trials of drug treatments for recurrent or high-grade meningiomas
Recovery after surgery
Most people stay in hospital for several days. Fatigue, headaches and concentration problems can last weeks to months. Rehabilitation helps with any weakness, speech or balance problems. Driving restrictions often apply after seizures or brain surgery.
Outlook
The outlook for grade 1 meningioma is generally excellent, especially when fully removed. Recurrence after complete removal of a grade 1 tumor is roughly 7 to 25 percent over 10 years, higher after partial removal. Grade 2 and 3 tumors recur more often and need closer follow-up. Long-term MRI monitoring is standard.
Frequently asked questions
Is a meningioma cancer?
Most meningiomas, about 80 percent, are benign grade 1 tumors that do not spread. A minority are atypical (grade 2) or malignant (grade 3) and behave more aggressively. Even benign meningiomas can cause problems by pressing on the brain.
What are the symptoms of a meningioma?
Many cause no symptoms. When they do, symptoms depend on location and include headaches, seizures, weakness, vision or hearing changes, loss of smell, memory problems and personality changes.
Does a meningioma always need surgery?
No. Small meningiomas without symptoms are often monitored with regular MRI scans. Surgery or radiation is recommended for meningiomas that cause symptoms, grow, are large or are higher grade.
How fast do meningiomas grow?
Most grade 1 meningiomas grow very slowly, often a millimeter or two per year, and some do not grow at all. Atypical and malignant meningiomas grow faster. Serial MRI scans show each tumor's growth rate.
Can a meningioma come back after surgery?
Yes, especially if part of the tumor could not be removed or it is a higher grade. Regular MRI follow-up detects recurrence early, and radiation or repeat surgery can then be used.
Sources
This guide was written from current patient and clinical guidance, including:
- National Cancer Institute: Meningioma
- American Association of Neurological Surgeons: Meningiomas
- American Brain Tumor Association: Meningioma
- Central Brain Tumor Registry of the United States (CBTRUS) Statistical Report
- World Health Organization Classification of Tumours of the Central Nervous System (5th edition, 2021)
- National Comprehensive Cancer Network (NCCN): Central Nervous System Cancers guidelines