Meningioma

A meningioma is a tumor that arises from the meninges — the membranes that surround your brain and spinal cord. Although not technically a brain tumor, it is included in this category because it may compress or squeeze the adjacent brain, nerves and vessels. Meningioma is the most common type of tumor that forms in the head. 

Most meningiomas grow very slowly, often over many years without causing symptoms. But in some instances, their effects on adjacent brain tissue, nerves or vessels may cause serious disability. 

Meningiomas occur most commonly in women, and are often discovered at older ages, but a meningioma may occur at any age. 

Signs and symptoms of a meningioma typically begin gradually and may be very subtle at first. Depending on where in the brain or, rarely, spine the tumor is situated, signs and symptoms may include:

• Changes in vision, such as seeing double or blurriness
• Headaches that worsen with time
• Hearing loss or ringing in the ears
• Memory loss
• Loss of smell
• Seizures
• Weakness in your arms or legs

It isn't clear what causes a meningioma. Doctors know that something alters some cells in your meninges to make them multiply out of control, leading to a meningioma tumor. 

The treatment you receive for a meningioma depends on many factors, including: 

• The size and location of your meningioma 
• The rate of growth or aggressiveness of the tumor 
• Your age and overall health 

Meningiomas can be easy to cure with surgery if the tumor is located on the front or surface convexity of the brain. Patients may have almost no symptoms at all until the tumor has grown to be very large. In contrast, some patients come in with a small tumor and say they've started to notice symptoms. Depending on the location of the tumor, meningioma can cause seizures, headaches, or changes in vision, smell or hearing. 

For the majority of patients, we see for meningioma, especially those whose tumors are asymptomatic, the first step is to monitor the tumor with periodic MRI scans. Serial imaging with MRI is very reasonable if the tumor is small and the patient has no symptoms. In contrast, if the tumor is causing symptoms such as double vision, weakness in the limbs, blindness, paralysis or a seizure, then neurosurgeons need to determine whether surgery is an option. Ideally, surgical removal of meningioma entails removal of a one-centimeter margins all the way around the tumor. However, this type of resection is not always possible, especially in the skull base. These deep-seated tumors in the skull base require referral to a skull base neurosurgeon. 

For patients who are not good candidates for surgery, have recurring tumors, or have requested it, we offer radiosurgery as a second option. Gamma Knife stereotactic radiosurgery is the most accurate radiosurgery system available — and when you're delivering such a high dose of radiation to the brain, you want to be as accurate as possible. In contrast to surgery, Gamma Knife stereotactic radiosurgery does not remove a tumor in the same way that surgery does; rather, radiosurgery inactivates the tumor and stops it from growing. Hence, the patient will need frequent serial MRI scans to monitor tumor growth or lack thereof. 

At Penn Medicine, we have many different treatment options. If Gamma Knife is not an option, we might consider Cyber Knife, or we might consider using proton radiation therapy. In addition to traditional surgery the Penn neurosurgery department are well-versed in minimally invasive endoscopic techniques such as purely endonasal means of removing specific skull base tumors. Penn Medicine's Center for Precision Surgery enables us to offer a unique surgery using a fluorescent dye that makes tumor cells glow to help ensure the entire tumor is removed. After a meningioma is removed, physicians in the Penn Center for Personalized Diagnostics can analyze the tumor for specific targetable mutations that we may be able to treat with a targetable medication.