Meningiomas are brain tumors that arise from the meninges and push into the brain, which cover the brain and spinal cord. Most meningiomas are benign, but some are more aggressive. Some patients have no symptoms, while others will have symptoms arising from pressure on the brain by the tumor. Not all patients require immediate treatment, but those who do may need meningioma surgery, stereotactic radiosurgery at a Gamma Knife center and/or fractionated radiotherapy.
Approximately 98-99 percent of meningiomas are benign, occurring twice as often in women. Grade II (~8-10%) lesions recur more frequently and are more aggressive, but they are not considered to be malignant. Grade III tumors are the ones considered to be malignant (1-2%) and are found more frequently in men. Meningioma development tends to occur during middle age, and female hormones may play a role.
Symptoms and Diagnosis of Meningioma
Meningioma symptoms depend on the tumor’s size, location and grade, as well as the area of the brain that is impacted. Symptoms may include:
- Nausea and/or vomiting
- Problems with hearing or vision
- Cognitive and memory issues
- Muscle weakness
Some patients without symptoms learn of a meningioma incidentally, when the doctor orders tests for another condition. Meningiomas can be detected using diagnostic imaging, such as computed tomography (CT) scans and magnetic resonance imaging (MRI).
Meningiomas are categorized into three grades based on how aggressive they are. This determination is made by a pathologist and requires a biopsy. The three grades are:
- Grade I/Benign: the most common and least aggressive form
- Grade II/Atypical: grows quickly than Grade I tumors, includes subtypes:
- Atypical meningioma
- Meningioma that has grown into the brain
- Chordoid meningioma
- Clear cell meningioma
- Grade III/Malignant or Anaplastic: the most aggressive form, most likely to return following treatment
Treatment of Meningioma
A doctor will recommend a treatment plan for a patient based on the individual’s overall health, tumor grade, size and location. Possible meningioma treatments include:
- Monitoring: This wait-and-see approach is used for tumors that are growing at a slow rate and not showing symptoms.
- Meningioma Surgery: Surgery is used in most cases, and as much of the tumor is removed as is possible. Radiation is reserved for those tumors that show regrowth after resection or if some of the tumor cannot be removed safely. Grade II and Grade III lesions may get radiation immediately after surgery without waiting for recurrence.
- Stereotactic Radiosurgery: Using technology such as Leksell Gamma Knife®Icon™, focused radiation is delivered directly to the tumor while sparing surrounding healthy tissue.
- Fractionated Radiotherapy: Multiple low-dose radiation sessions are delivered to the meningioma, which is effective in stopping the growth of meningiomas in the majority of cases.
The prognosis depends on the patient’s health condition in combination with the tumor grade. Lower-grade tumors are less aggressive and typically carry a more favorable prognosis. However, the doctor will be able to give the patient a personalized prognosis based on their unique condition.