Definition: A meningioma is a tumor that grows from the lining around the brain. The World Health Organization classifies meningiomas as grade I (benign), grade II (atypical) or grade III (anaplastic) based on how quickly the tumor cells are dividing. The majority of meningiomas are benign and grow very slowly.
Symptoms: Symptoms that occur due to meningiomas depend on their location and how much pressure they exert on the brain. Many meningiomas are asymptomatic and are incidentally discovered on imaging of the head done for unrelated reasons such as after a head injury.
Evaluation: Meningiomas are evaluated with an MRI or a CT scan.
- Continued observation: Regular MRI’s of the brain will be performed to watch for tumor growth if the meningioma is not causing any symptoms. Surgical removal of the tumor will be considered if the tumor starts to grow and put pressure on the brain or cause symptoms.
- Surgery: The treatment of choice for meningiomas that cause symptoms is surgical removal. Some meningioma’s cannot be removed completely because of their location near critical brain structures such as the brainstem, blood vessels, or nerves.
- Radiation therapy recommended for portions of a meningioma that could not be removed with surgery and continues to grow or recurrent meningiomas, especially if they are atypical or anaplastic.
Follow-up: The recurrence rate of benign meningioma’s that are completely removed during surgery is approximately 4%. The recurrence rate for partially removed meningiomas is higher. The recurrence rate of atypical and anaplastic meningiomas is the highest. All patients must have regular follow-up MRI’s or CT scans of the brain after removal. How often will be determined according to the grade of the tumor and how much of the tumor was removed.