Meningiomas are brain tumors that develop in the meninges, the tissue that surrounds and protects the brain and spinal cord (figure 1). Although most meningiomas are not cancerous, these tumors can cause problems as they grow and press against important parts of the brain or spinal cord. The cause of meningiomas is not well understood, but may include both genetic (inherited) and environmental factors.
Meningiomas can occur in any part of the lining over the brain or spinal cord. About 90 percent occur within the head: inside the skull, at the base of the skull, or just above the spinal cord (the brainstem). Meningiomas can also occur around the spinal cord or in an area called the optic nerve sheath, which protects the nerve connecting the eye to the brain.
Meningiomas can be managed with observation, surgery and/or radiation therapy. In some cases, active intervention may be delayed and will only start if the tumor begins to grow.
More detailed information about meningiomas is available by subscription. (See "Meningioma: Clinical presentation and diagnosis" and "Treatment of benign (WHO grade I) meningioma".)
Many people with meningiomas will have no symptoms. Other people develop neurologic symptoms such as seizures, changes in vision or hearing, or arm or leg weakness.
●Seizures — Seizures may cause a person to pass out, stiffen, or have jerking muscle movements. Some seizures are more subtle, causing changes in your senses (eg, smelling a scent that is not really there). (See "Patient information: Seizures in adults (Beyond the Basics)".)
●Visual changes — Meningioma can cause partial or complete loss of vision, typically in one eye. There may also be other changes in vision, such as blind spots or blurred or double vision. Some people with meningioma do not notice these changes.
●Hearing loss — Meningiomas can cause hearing loss.
●Changes in thinking — People with large meningiomas may have subtle changes in their personality or thinking, causing the person to appear forgetful or to have trouble paying attention.
●Arm and/or leg weakness — A meningioma can cause weakness in the arms, legs, or both, depending upon the location of the tumor.
●Headaches, nausea, and vomiting — As a meningioma grows, its increasing size can increase the pressure inside the skull. This can lead to headaches, nausea, and vomiting. In some people, the meningioma can block the flow of spinal fluid around the brain and spinal cord. This can also increase pressure in the skull and cause the same symptoms.
Meningioma is usually diagnosed after a scan of your brain, usually an MRI. MRI gives a detailed image of the brain and can show if there is a tumor, especially if contrast material is given.
In some cases, a meningioma is found after a CT scan or MRI is done for another reason (such as after a head injury). In other cases, a scan is done because of new or worrisome symptoms, like seizures.
The best treatment for a meningioma depends upon the tumor's size, how fast it is growing, where it is located, and your age and health. When deciding which treatment is best, you and your doctor must also consider the potential benefits of treatment (ie, reducing symptoms and preventing further tumor growth) and the potential side effects and risks of treatment.
Meningiomas are divided into three categories, based upon how quickly the tumor is growing and how likely it is to come back after treatment:
●Grade I or benign meningiomas — Benign (non-cancerous) meningiomas are slow-growing tumors that often do not affect nearby normal brain. Benign meningiomas are the most common type, making up 70 to 80 percent of all meningiomas. Many benign meningiomas do not need any treatment. Most benign meningiomas that are treated do not come back after treatment.
●Grade II or atypical meningiomas — Atypical meningiomas usually grow more rapidly than benign meningiomas and have a higher chance of growing back after treatment.
●Grade III, anaplastic, or malignant meningiomas — Malignant meningiomas are a form of brain cancer, and are most likely to grow back after treatment. These are rare, making up about 2 to 3 percent of all meningiomas.
Treatment of a meningioma may include surgery, radiation therapy, or watching and waiting (called active surveillance). (See "Treatment of benign (WHO grade I) meningioma".)
Surgery — Surgery is the preferred treatment for most meningiomas, especially for tumors that are large, growing quickly, or causing symptoms. The goal of surgery is to remove as much of the tumor as possible. However, this is not always possible, depending upon the size and location of the meningioma. In addition, some tumors cannot be totally removed because the tumor is too close to or involved with important parts of the brain or blood vessels. In such cases, the tumor may be only partially removed.
After surgery, it is possible that the tumor will come back. This risk depends upon how much tumor was removed and whether it was benign, atypical, or malignant. If the tumor is not removed completely with surgery, radiation therapy is often recommended after surgery to reduce the risk of it coming back (see 'Radiation therapy' below).
Complications of surgery — Possible complications of surgery include damage to nearby normal brain tissue, bleeding, and infection. Potentially serious complications can include:
●Temporary accumulation of fluid in the brain (cerebral edema) is common after surgery for meningiomas. A medication may be given before and after surgery to minimize this problem.
●About 20 percent of people who did not have seizures before surgery will develop them after surgery. Anti-seizure medication is usually recommended after surgery, and is slowly discontinued after surgery if seizures do not occur. (See "Patient information: Seizures in adults (Beyond the Basics)".)
●After surgery, some people develop neurologic problems, such as muscle weakness, speech problems, or difficulty with coordination. These symptoms depend on where the tumor was located. Many times, these symptoms go away after a few weeks.
●People who have brain surgery or who have brain tumors have an increased risk of blood clots in the veins (deep venous thrombosis) and lungs (pulmonary embolism). As a result, treatments to prevent blood clots are recommended during and after surgery. (See "Patient information: Deep vein thrombosis (DVT) (Beyond the Basics)".)
Radiation therapy — Radiation therapy uses high energy x-rays to damage tumor cells. The x-rays are carefully aimed at the area of the brain affected by the tumor. Unlike normal cells, tumor cells are less able to repair the damage caused by radiation. The area of the brain treated is carefully calculated to deliver the greatest amount of radiation to tumor cells while minimizing radiation exposure to the normal brain tissue.
Radiation therapy is often recommended after surgery or if surgery is not possible. If surgery is done, radiation therapy is usually started after the person has fully recovered from surgery.
There are different ways to deliver radiation therapy. Decisions about radiation therapy should be made by a radiation oncologist. He or she will consider the size and location of the area that needs treatment, any current symptoms, potential side effects of treatment, your general health, and any prior treatments you had.
●Radiation treatment may be given in multiple small doses. This is called fractionated radiation therapy. This is done five days per week for five to six weeks, and each treatment lasts only several seconds. You do not feel the radiation, similar to having an x-ray.
●Radiation treatment may also be done as stereotactic radiosurgery. This does not actually involve performing surgery, but instead uses narrow beams of radiation that are delivered from multiple angles. This allows a very high dose of radiation to be delivered to a small spot. Stereotactic radiosurgery is given as a single or limited number of treatments to small tumors.
Side effects of radiotherapy — Unfortunately, radiation therapy cannot stop all tumor cells from growing without risking damage to nearby normal brain tissue. Fortunately, side effects are not usually serious or life-threatening.
During fractionated radiation treatment, hair loss will occur, typically starting around the third or fourth week of treatment. Hair loss usually occurs in areas where treatment occurs; this may be temporary or permanent. Hair usually begins to regrow two to three months after treatment ends.
Mild fatigue is common and often does not develop until the last few weeks of radiation treatment. Mild skin redness or irritation may occur and is temporary. Headaches and nausea occur infrequently during radiation therapy, and can be treated if needed.
Stereotactic radiosurgery is tolerated very well, typically with minimal or no symptoms. The most common of possible symptoms are mild brief fatigue and mild temporary headaches.
Active surveillance — It is often possible to postpone treatment and watch a meningioma closely. This is called active surveillance or watchful waiting. Active surveillance may be an option if a meningioma is small, growing slowly, and is not causing symptoms.
Active surveillance may also be recommended for people who are older (who have a higher risk of treatment-related side effects) or those who have other serious medical problems.
With active surveillance, you will need to be examined and have an MRI or CT scan of the head periodically. This is usually done three to six months after the first brain scan, then once per year, assuming that the meningioma does not grow or cause symptoms during this time. If the tumor begins to grow or cause symptoms, treatment is recommended.
Treatment if the tumor grows back — If a meningioma grows back after treatment, it may be possible to have more surgery or radiation treatment. (See "Treatment of benign (WHO grade I) meningioma".)
Progress in treating meningioma requires that better treatments be identified through clinical trials. A clinical trial is a carefully controlled way to study the effectiveness of new treatments or new combinations of known therapies. Clinical trials are conducted in many countries around the world. Ask for more information about clinical trials, or read about clinical trials at:
WHERE TO GET MORE INFORMATION
Your healthcare provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.
Patient information: Brain cancer (The Basics)
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Patient information: Seizures in adults (Beyond the Basics)
Patient information: Deep vein thrombosis (DVT) (Beyond the Basics)
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
Meningioma: Clinical presentation and diagnosis
Classification of gliomas
Risk factors for brain tumors
Spinal cord tumors
Treatment of benign (WHO grade I) meningioma
The following organizations also provide reliable health information.
●National Cancer Institute
●American Society of Clinical Oncology
●Brain Science Foundation
Patient support — There are a number of online forums where patients can find information and support from other people with similar conditions.
●About.com Cancer Forum
●Meningioma Mommas Online Support Group
The editorial staff at UpToDate, Inc. would like to acknowledge Dr. Peter Black, who contributed to an earlier version of this topic review.