What Is Meningioma?
A meningioma is a tumor that forms on the membranes that cover the brain and spinal cord just inside the skull. These membranes are called the meninges and consist of three layers. Specifically, the tumor can form on any of these three layers. These tumors are often slow-growing. Around 80% are benign (not cancerous).
Most meningiomas occur in the brain. But they can also grow on parts of the spinal cord.
Often, meningiomas cause no symptoms and require no immediate treatment. But the growth of benign meningiomas can cause serious problems. In some cases, such growth can be fatal.
Meningiomas are the most common type of tumor that originates in the central nervous system. They occur more often in women than in men.
Meningioma Grades
Meningiomas are classified by location and severity.
Grade 1 meningiomas
These are the most common type of meningioma. About 80% of grade 1 tumors are benign (not cancerous). They grow slowly and have defined borders.
Grade 2 atypical meningiomas
About 15%-20% of meningiomas are classified as atypical. These are considered neither benign nor malignant (cancerous), but they may become malignant. These tend to return and grow quickly when they do.
Grade 3 anaplastic meningiomas
A small number, about 1%-4% of meningiomas are cancerous. They tend to grow quickly, spreading to parts of the brain closest to the tumor. They can also spread to other parts of the brain and beyond, often to the lungs.
Meningioma Causes
Researchers are unsure what exactly causes meningioma, but cancers generally result from changes in our genes. Researchers have found an abnormality on chromosome 22, which works to keep tumors from growing, in about 40%-80% of meningiomas. Radiation exposure, particularly as a child, may increase your risk of developing a meningioma. People with neurofibromatosis type 2, a genetic condition, are also at a higher risk for meningioma.
Meningioma Risk Factors
Potential risk factors for meningioma include:
Gender. Meningiomas are more common in women and people assigned female at birth (AFAB), and middle-aged women are more than twice as likely as men to develop a meningioma. It's thought this risk factor may be due to female hormones. Most meningiomas occur between the ages of 30 and 70. They are very rare in children.
Hormone replacement therapy. The hormones estrogen, progesterone, and androgen are believed to play a role in meningioma. Meningioma cell surfaces have receptors for estrogen, progesterone, or both. Meningiomas grow more rapidly in pregnancy when the body naturally creates more of these hormones. Because the body receives a boost of hormones during hormone replacement therapy, it's thought that it may also play a role in the growth of meningiomas.
Radiation exposure. Research has indicated that radiation exposure, particularly to the head and neck, increases the risk of meningiomas and other brain tumors.
Use of oral contraceptive pills. Like hormone replacement therapy, oral contraceptives raise hormone levels and may increase your risk for meningioma.
Breast cancer diagnosis. A direct link between breast cancer and meningioma hasn't been determined. But the two conditions share some of the same risk factors such as age, gender, and hormones.
Head injury. Previous head injury may also be a risk factor, but a recent study failed to confirm this. Meningiomas have been found in places where skull fractures have occurred. They've also been found in places where the surrounding membrane has been scarred.
Age. Meningiomas are more common in people over the age of 65.
Race. Black people have a higher risk for meningioma.
Obesity. The link between meningiomas and obesity is unclear, but obesity is a risk factor for multiple cancers, and some research has shown that meningiomas occur more frequently in people with obesity.
Genetic conditions. People with the genetic condition neurofibromatosis type 2 (NF2) have around a 50% chance of developing meningioma. Other genetic diseases carrying an increased risk of meningioma include Cowden syndrome, Werner syndrome, Rubinstein-Taybi syndrome, and basal cell carcinoma syndrome (Gorlin syndrome).
Other potential risk factors. In addition, long-term use of cell phones, epilepsy, smoking, and ongoing exposure to lead may be associated with meningiomas.
Meningioma Symptoms
Most meningiomas grow very slowly, so their symptoms often develop gradually, if they develop at all. Symptoms also depend on where in your brain the meningioma is located. The most common symptoms include:
- Headaches
- Seizures
- Blurred vision
- Weakness in arms or legs
- Numbness
- Speech problems
Meningioma Diagnosis
Meningiomas are rarely diagnosed before they begin to cause symptoms.
If symptoms indicate the possibility of a tumor, a doctor may order a brain scan: an MRI and/or a CT scan. These will allow the doctor to locate the meningioma and figure out its size.
A biopsy may sometimes be performed. A surgeon removes part or all of the tumor to check whether it is benign or malignant.
Meningioma Treatment
Meningioma treatment depends on multiple factors such as the tumor's size and growth rate as well as your health, age, and treatment preferences. Options include:
Wait and watch
If the tumor is not causing any symptoms, observation is often recommended. Regular brain scans will be performed to check if the tumor is growing. If your tumor's growth threatens to cause problems or if symptoms begin to develop, surgery may be necessary, particularly if:
- You have symptoms such as seizures, blurred vision, tinnitus or loss of hearing, memory issues, severe headaches, or weakness in your limbs.
- The meningioma is located in a vital area such as close to your spinal cord or major blood vessels.
- Your tumor is cancerous.
Meningioma surgery
If surgery is required, a craniotomy will typically be performed. This involves removing a piece of bone from the skull. This gives the surgeon access to the affected portion of your brain. The surgeon then removes the tumor — or as much of it as possible. The bone that was removed at the start of the procedure is replaced.
Any post-surgery treatment you may need depends on whether:
- There is no visible tumor remaining
- Your tumor is noncancerous, with only a small amount left
- Your tumor is cancerous or irregular
Depending on where in the brain your tumor is located, surgery may involve some significant risks that you should discuss with your doctor.
Radiation therapy
The location of the meningioma will decide how accessible it is to the surgeon. If it can't be reached via surgery, radiation therapy may be used. Radiation can shrink the tumor or help prevent it from growing any larger. Radiation can also be used to kill cancer cells if the tumor is malignant. It may also be used on the parts of a tumor the surgeon was unable to remove.
Chemotherapy
Doctors rarely use chemotherapy to treat meningiomas because there isn't a standard treatment for doing so. However, it may be used at times when surgery or radiation hasn't been effective.
Meningioma Survival Rates
Survival rates for cancers such as meningioma depend on multiple factors. The overall survival rates by age for meningioma are as follows:
- 84% for people aged 2–44
- 79% for those aged 45-54
- 74% for those aged 55-64
An analysis of more than 60,000 patients found that survival rates worsen depending on where the meningioma is located, whether the meningioma is cancerous or larger in size, and if a patient is older or has other chronic health conditions. Also, uninsured people usually have worse outcomes.
The lower the grade of your tumor, the more likely that surgery combined with radiation will improve your prognosis. Surgical removal of all of the tumor and affected areas is associated with a lower rate of recurrence as well. Recently, the 10-year survival rate for those with cancerous meningiomas has improved because of new treatment options.
Meningioma Complications
Meningiomas usually grow slowly, so you may not notice any symptoms at first. But as they begin to increase in size and impact the brain areas surrounding them, you may begin to feel symptoms that depend on where your meningioma is located. These symptoms may include:
- Paralysis of your lower limbs
- Loss of smell
- Eye bulging
More commonly, you might have:
- Vision changes such as double vision, blurriness, or vision loss
- Hearing loss
- Headaches
- Nausea, vomiting, and dizziness
- Seizures
- Changes to your personality or behavior
- Problems with memory
- Neurological problems including poor muscle tone, weakness, and low or no reflex responses
Postsurgical complications can include:
- Swelling or fluid accumulation in your brain that may lead to brain damage
- Injury to nerves in your brain that might affect your vision, hearing, and facial or swallowing muscles
- Accidental injury to normal tissue that may cause neurological problems
- Infection
- Spinal fluid leaks
- Brain bleeding
- Worsening neurological symptoms
- An increased risk of blood clots in the veins and lungs
Takeaways
A meningioma is a tumor that grows on the membranes just inside your skull that cover the brain and spinal cord, known as the meninges. Meningiomas usually grow slowly, sometimes developing for years before you feel any symptoms. Around 80% of meningiomas are noncancerous (benign), but they can cause changes to your senses, memory, and neurological functions. See your doctor immediately if you have a sudden onset of symptoms such as seizures, vision changes, or memory loss.
Meningioma FAQs
What is meningioma cancer?
Meningioma is a type of tumor that grows on the membranes between the skull and the brain and spinal cord. Technically, they are not tumors in your brain, but their growth can press against nearby brain tissue, nerves, and blood vessels, causing symptoms. Meningioma is the most common head tumor. Around 80% of meningiomas are not cancerous.
What size meningioma needs to be removed?
Because meningiomas are typically slow-growing, several factors decide whether one should be surgically removed. These factors include the tumor's size and rate of growth, the patient's age and health, and whether the tumor is causing neurological problems.
What is the life expectancy after meningioma surgery?
Outcomes depend on whether the meningioma is malignant (cancerous) or benign and whether surgery succeeds in removing all of the tumor. The overall survival rate by age for meningioma is 84% for people aged 20-44, 79% for those aged 45-54, and 74% for those between the ages of 55 and 64.
Can an MRI tell if a meningioma is benign?
Researchers have found that brain imaging tests such as MRI and CT scans can help detect the difference between a cancerous or benign meningioma. However, surgical biopsy will give the most definitive answer.
Can you die from a benign meningioma?
People who have benign meningiomas are more likely to die from other health conditions such as heart and cardiovascular disease, stroke, and dementia. Fewer than 9% of people died from benign meningiomas in one population-based study.
How to prevent meningioma
Doctors aren't sure what causes meningiomas, but it's believed that many or most are genetic in origin and some may be related to hormones or particular environmental factors. Meningioma is more common in people over 65, women and people AFAB, Black people, and people who've been exposed to radiation of the head. Having a sibling or parent diagnosed with meningioma or having certain genetic conditions can also raise your risk.
