Our brains are covered by a thin layer of tissue, known as the dura, which can sometimes give rise to tumors. Called meningiomas, these brain tumors are most often found near the top and the outer curve of the brain, or at the base of the skull and pushing on the brain (as opposed to arising in it). Most meningiomas are benign and slow-growing. However, each year approximately over 350 people in the U.S. are diagnosed with atypical or anaplastic meningiomas, which mean they can spread to other parts of the body.
Doctors at Yale Medicine are experts in the management of meningiomas. The brain tumor surgeons are specialized in removing these tumors safely and effectively, leading to better patient outcomes. The Yale Medicine Gamma Knife Center uses precisely directed radiation to treat such tumors when necessary.
"Coming to a place like Yale, with doctors who are dedicated solely to helping patients with these types of brain tumors, is incredibly important to ensuring appropriate care," says Jennifer Moliterno, MD, a Yale Medicine specialized meningioma brain surgeon. "We understand the diagnosis can be extremely scary for anyone, and we are here to help every step of the way.”
What are the different types of meningiomas?
Doctors grade brain tumors by how aggressive they are, based on the World Health Organization (WHO) Classification.
In the case of meningiomas, a Grade 1 tumor is the most benign and slow-growing, and is the most frequently occurring type.
Grade 2, or atypical meningiomas, are more likely to invade the brain and have a higher risk of growing back after surgery. Therefore, patients with atypical meningiomas usually receive radiation after surgery.
The remaining tumors are classified as Grade 3, or anaplastic or malignant meningiomas. They behave quite aggressively and have an even higher rate of recurrence than atypical tumors.
What are symptoms of a meningioma?
The location of a brain tumor, along with its size, usually determines its symptoms.
For example, a meningioma that is putting pressure on the region of the brain controlling speech will affect the person’s ability to talk. Similarly, a meningioma near the "motor" part of the brain can cause weakness, while one pushing on the visual cortex can interfere with sight.
All brain tumors can cause headaches and most can lead to abnormal electrical activity in the brain, or seizures. Still, many meningioma grow so slowly that symptoms occur gradually and may be subtle. Some patients with tumors never notice symptoms of any kind.
How are meningiomas diagnosed?
The most reliable way to diagnose meningiomas is by using magnetic resonance imaging (MRI). Doctors also occasionally find meningiomas during routine scans for other evaluations, such as headaches or even for unrelated head injuries. In that case, if the tumor is small and not causing symptoms, it will simply be monitored over time.
However, if the tumor is large or is causing problems, treatment should be pursued.
How are meningiomas treated?
Meningiomas that cause neurological problems for a patient require treatment, usually surgery. Tumors that are not causing symptoms are typically examined using MRI to learn about their size, speed of growth (as estimated by multiple scans over time), and location. Those factors, along with the patient’s age and overall medical health, are weighed when considering whether the meningioma should be treated or followed closely.
The expected lifetime of the patient is factored in treatment decisions: If a 75-year-old patient has a tumor, it probably won’t grow enough in his or her lifetime to affect health or quality of life. But a similar tumor of the same size and growth rate in a 30-year-old will likely need to be surgically removed.
Because the vast majority of meningiomas are slow-growing, a more conservative approach to treatment is typically advised than with other, more aggressive brain tumors. A smaller, asymptomatic meningioma may be monitored with regular MRI scans rather than being removed. Many will never grow to significant size or become symptomatic.
If a tumor causes symptoms, is large, or shows growth during close monitoring over time, surgery is usually the best treatment option. For most patients, especially those with Grade 1 meningioma, successful surgery will remove the tumor completely. For patients for whom surgery is not an optimal choice, targeted radiation therapy (such as Gamma Knife Radiosurgery) can be used to help stop the growth of the tumor.
While surgery is typically the end of treatment for benign meningiomas, patients continue to have scans performed regularly to be sure that the tumor does not come back.
As discussed above, Grade 2 and Grade 3 meningiomas require surgery and radiation will often be given afterwards. Once removed, these tumors are evaluated by experienced neuropathologists who determine the diagnosis. The patient and his/her tumor is then discussed at a multidisciplinary tumor board, where doctors who are dedicated to treating meningiomas and other types of brain tumors meet to determine the best possible treatment plan for each individual patient.
What are the risk factors for meningioma?
The cause of meningiomas are not known.
However, studies haven shown that people treated with high doses of radiation to the head have an increased likelihood of developing them. For instance, children treated aggressively for childhood leukemia, with repeated radiation of their entire brain and skull, are at a higher risk of developing meningiomas later in life. Some conditions, such as neurofibromatosis Type 2, carry a higher risk for meningioma formation. The use of cell phones does not appear to increase the risk.
What makes Yale Medicine's approach to meningioma unique?
Yale Medicine's first priority is the patient. Ensuring an adequate diagnosis and determining the best management plan is the sole focus.
Yale Medicine researchers study genetic mutations that could lead to the potential to develop medical therapies personalized to each patient, which may, over time, reduce the need for surgery.
"Yale Medicine is able to manage the full spectrum of the patient’s care with the cutting-edge expertise of a large academic center, but with the feel, compassion, and approachability of a smaller community hospital" says Dr. Moliterno.