What is a meningioma?
Meningiomas are tumors found next to the brain. They come from the meninges, which are layers of tissue that cover the brain and spinal cord, most often the arachnoid cells. They tend to grow slowly and inward. Often they will have grown quite large before they are diagnosed. While they are usually benign (not cancer), they can still grow large enough to be life-threatening. Tumors that are cancer are called malignant. Some patients may have more than one meningioma. Meningiomas account for about one-third of all primary brain tumors. There are three types of meningioma by grade:
- Grade I, (benign meningioma), which grows slowly
- Grade II (atypical meningioma), which grows more quickly
- Grade III (anaplastic/malignant meningioma), which grows and spreads quickly
These types of tumors are also called by names that indicate where they are found and by the types of cells that show up under the microscope.
Where are meningiomas most commonly found?
Most of these tumors are found on the outer surface of the brain. Often, they are found at the top of the brain. Sometimes, they can develop at the base of the skull.
Symptoms and Causes
What are the causes of meningiomas?
Research has shown that 40%-80% of all meningiomas have an abnormality in chromosome 22, which is involved in the suppression of the growth of tumors. This may occur spontaneously or part of a family history of neurofibromatosis type 2 or breast cancer. Previous radiation to the head is another risk factor. There is a correlation between hormones and meningiomas.
What are the signs and symptoms of meningiomas?
The most common signs are headaches and weakness in a hand or foot. Some symptoms are related specifically to the area of the brain that has the meningioma.
Other symptoms include:
- Problems seeing and/or hearing
- Personality changes
- Nausea and vomiting
- Twitching and seizures
- Facial numbness or pain
Diagnosis and Tests
How are meningiomas diagnosed?
Diagnosing meningiomas can be difficult due to the slow rate at which they grow. Often, the symptoms are attributed to aging. Thorough neurological exams are needed, the diagnosis is most often made with radiological tests. Other tests such as hearing and vision tests may be used to determine how a meningioma is affecting the brain.
What tests are used in diagnosing meningiomas?
Computed tomography (CT scans) and magnetic resonance imaging (MRI) are often used in the diagnosis. A full diagnosis may require a biopsy, however, sometimes the diagnosis can be made by CT or MRI alone. On rare occasions, a cerebral angiogram may be used to determine the source of blood to the tumor, or how the tumor is affecting blood flow in the brain.
Management and Treatment
How are meningiomas managed and treated?
Radiosurgery and surgery are the most common initial treatments. When surgery is used first, radiation (either radiosurgery or daily treatments) is reserved for recurrent tumors or some tumors that cannot be completely removed by surgery Anaplastic/malignant tumors will be treated with radiation therapy. In some cases, the best management is simply close observation. Chemotherapy is only rarely used, and is usually for malignant or atypical types of meningiomas or grade 1 meningioma when they have failed prior surgery and or radiation. Corticosteroids and/or antiepileptic medications may be used pre- and post-operatively.
When should someone with a meningioma contact their healthcare provider?
A patient who notices new and different symptoms should report the changes to his or her provider immediately.
Who is at risk for developing meningiomas?
Meningiomas can affect anyone. Women account for two-thirds of all meningiomas. However, malignant meningiomas are found more often in men. Also, they are most often found in adults between 30 and 70 years of age. These tumors are more commonly found in Africa than Europe or North America. In the United States, there are about two cases of symptomatic meningiomas per 100,000 persons annually.
Outlook / Prognosis
What is the prognosis for someone with meningioma?
Better outcomes are associated with a surgical removal of the entire tumor or radiosurgery. The younger the patient is at time of diagnosis, the better the long-term prognosis. The Central Brain Tumor Registry of the United States reports a 57.4% ten-year relative survival rate for patients with malignant meningiomas. For people with non-malignant meningioma, the 10-year relative survival rate is 81.4%. The rates may differ depending upon the location of the meningiomas. (In terms of cancer, the 10-year survival rate is the percentage of people who are still alive 10 years after being diagnosed.)
Visit our Brain Tumor Guide to learn more about the different types of brain tumors and treatment options from Cleveland Clinic experts.