The meninges are a thin, durable layer of tissue that covers the brain and spinal cord. A meningioma is a tumor that forms from this covering and can grow outward or inward, pressing into the brain. Meningioma causes are not well understood, but they may be related to hormones. This could be why they are more common in women than men and tend to occur between ages 30-70.
Most meningiomas are benign. However, this does not mean they are harmless, and they do still have the potential to be aggressive.