A meningioma is a tumor of the protective lining of the brain and spinal cord. This lining is called the meninges. Most meningiomas are benign (noncancerous), though some may be malignant (cancerous). Benign meningiomas are generally slow growing. This type of tumor may not cause problems. But, if the meningioma grows, it can compress important parts of the brain or cause symptoms (eg, vision problems, seizures).
Malignant meningiomas (also called aggressive or anaplastic) are less common. These tumors are faster growing. They often cause problems and can cause some swelling in the brain. Often both benign and malignant meningiomas require some form of therapy, surgery, and/or radiotherapy depending upon location.