What is a meningioma?
A meningioma is a tumor that forms in the membranes that surround the brain and spinal cord.
Although more than 90 percent of meningiomas are benign and grow slowly, some are cancerous and can quickly spread to other organs of the body.
If left untreated, a meningioma can put pressure on the brain and lead to complications such as memory loss, loss of coordination or balance and seizures.
Causes of meningiomas
The exact cause of a meningioma is unknown, but there are several risk factors that increase your likelihood of developing one.
Risk factors for meningiomas
There are several factors that can increase your risk of developing a meningioma including:
- Gender — women are more likely to develop a meningioma, so research is being done on the link between progesterone and meningiomas.
- Radiation exposure — people who have been exposed to radiation in the head are at a higher risk for developing a meningioma.
- Obesity — people who are overweight or obese are more likely to develop a meningioma, but the link is not clearly understood.
- Neurofibromatosis 2 — people who have neurofibromatosis type 2, a nervous system condition that is inherited, are at higher risk for developing a meningioma.
Symptoms of meningiomas
Because meningiomas grow so slowly, many patients will not experience any symptoms or need treatment. Patients who experience symptoms typically present with:
- Vision abnormalities such as double vision or vision loss
- Memory loss
- Seizure episodes
- Fatigue in the arms and legs
- Problems speaking
- Loss of bladder control
Symptoms can progressively intensify as the tumor grows.
Diagnosis of meningiomas
Patients can live with a meningioma for years before experiencing symptoms. If you present at your primary care doctor with symptoms that indicate a brain tumor, your doctor will refer you to a neurologist for testing and treatment.
Your doctor will perform a neurological exam that will test your vision, hearing, balance, coordination and memory. If the tests indicate the presence of a meningioma, the doctor may order additional diagnostic tests such as:
- Computed tomography (CT scan) — can take detailed, cross-sectional images of the brain and spinal cord to determine if there are abnormal cell growths.
- Magnetic resonance imaging (MRI scan) — can take cross-sectional images of the brain using magnetic field and radio waves to locate any abnormal growths.
- Biopsy — your doctor may order a biopsy to determine what cells are causing the tumor. During a biopsy procedure, your doctor will take a small sample of tissue from the affected area and examine it under a microscope.
- Electroencephalogram (EEG) — an EEG is a noninvasive test that measures electrical activity in the brain and checks for seizures.
Treatment of meningiomas
Treatment protocols for meningiomas vary based on the size and location of the tumor, how fast the tumor is growing, your overall health as well as your goals of the treatment. Your doctor will work with you to determine the most appropriate treatment option for your case.
Treatment begins with observation. Patients with benign, slow-growing tumors that are not causing any symptoms may not need immediate treatment. If you fall into this category, your doctor may recommend regular monitoring and imaging tests instead of treatment. If the meningioma starts growing more aggressively or turns malignant, treatment may be necessary. Your doctor will determine the most appropriate treatment for your case.
After observation, surgery is the most common treatment for meningiomas. Patients who are experiencing symptoms or those who have aggressively growing tumors are the primary candidates for surgery. In many cases, surgeons can completely remove the tumor, providing symptomatic relief.
Some meningiomas are located very close to parts of the brain that are more delicate. In these cases, the entire tumor may not be able to be removed. Patients will typically experience symptoms relief even if the entire tumor is not removed, but many will have to be treated further with other modalities to destroy the cancerous cells.
Finally, radiation therapy is recommended when the tumor can’t be removed or can’t fully be removed with surgery, when the tumor is malignant or if the patient has a recurrent tumor. There are a variety of radiation therapy options used to treat meningiomas.
Stereotactic radiosurgery (SRS)
Stereotactic radiosurgery kills cancerous cells by using targeted, high doses of radiation directly to the tumor in the brain. The radiation damages the DNA in the abnormal cells, which destroys the cells. As a result, the tumors shrink. There are a variety of stereotactic radiosurgery technologies that are effective including a linear accelerator and Gamma Knife. During treatment with a linear accelerator, x-rays are delivered directly to the affected area of the brain to destroy cells. Treatment can be completed in one session or up to five for larger tumors. CyberKnife is a type of LINAC radiation therapy. Meanwhile, Gamma Knife is a radiation therapy used on small to medium size tumors. It works by providing targeted, small beams of gamma rays directly to the affected area.
Intensity-modulated radiation therapy (IMRT)
IMRT therapy is used on patients who have tumors that are located near delicate brain or spinal cord structures. During IMRT, precise radiation doses are delivered to the affected area of the brain.
Although chemotherapy is typically not used to treat meningiomas, your doctor may prescribe other medications such as anticonvulsants, corticosteroids or pain medicines to help relieve symptoms caused by the meningioma.