A meningioma is a type of tumor that's often discussed along with brain tumors, though it's not technically a brain tumor. This type of tumor grows in the meninges, which are layers of tissue that cover the brain and spinal cord.
These tumors are usually benign. This means that unlike cancerous tumors, they don't tend to spread to distant parts of the body. Because of their location, though, meningiomas can still cause neurological problems. As these tumors grow, they can compress the brain and spinal cord, leading to serious symptoms.
Meningiomas are the most common type of brain tumors in adults and occur more often than cancerous brain tumors. Children rarely get them, and they're more common in older adults. Women are also much more likely to get them than men. The underlying cause of meningiomas is not clear. Hormonal fluctuations may encourage the growth of these tumors, but more research is needed to confirm this.
These tumors usually grow slowly. You may not have any symptoms until the tumor has become large. The tumor can cause different symptoms, depending on where it's growing. These are possible symptoms:
Vision or hearing loss
Trouble thinking clearly
Loss of smell
Weakness in an arm or leg
Doctors often diagnose a meningioma using an MRI or CT scan. In addition, the doctor may want to remove a sample of the tumor to examine it under a microscope before making the diagnosis.
If your meningioma is causing symptoms or is growing, your doctor will likely want to remove it with surgery. In some cases, though, trying to remove the tumor may be too risky. For example, the tumor may be too close to a vital brain structure or blood vessel.
If you do have surgery, the surgeon will try to take out as much of the tumor as possible. The surgeon may use MRI images of your brain to help guide the surgery. The surgeon may also use a special microscope during the surgery to get a better view of the tumor and the surrounding parts of your brain.
If the surgeon can't remove the tumor—or can only remove part of it—you may need radiation therapy. Depending on the areas of the brain and/or spinal cord that are involved, radiation therapy may help shrink any remaining tumor and can also prevent it from spreading to the tissues around it. Even if the tumor is completely removed during surgery, some doctors may still recommend radiation therapy to help prevent another meningioma from developing in the future. Meningiomas have a tendency to grow back after surgery.
Your doctor may also recommend medications to treat the tumor. Experts are studying several drugs to see if they work against meningiomas. You may need to take part in a study in order to use these drugs.
You may also be able to use other drugs to treat symptoms caused by the meningioma, such as seizures, excessive vomiting, weakness, and vision disturbances.
In most people, meningiomas don’t cause any symptoms and grow quite slowly. For this reason, doctors will recommend using an approach called “watchful waiting.” This means you will report any new symptoms to your doctor, and your doctor will order scans on a regular basis to track even minor changes in the tumor. This may be a reasonable option for managing small tumors that aren't causing symptoms, especially in older adults who may not be able to undergo surgery or radiation therapy because of other medical conditions.