A meningioma is a common tumor that grows in the meninges (layers of tissue that cover the brain and spinal cord). A meningioma is often referred to as a brain tumor. But, it is not technically a brain tumor because it does not come from brain tissue.
In most cases, these tumors are not cancerous (they are usually benign). Unlike cancerous tumors, they normally do not spread to other parts of the body. But, meningiomas can lead to neurological problems due to their location. When they grow, they can press on the brain and spinal cord. This can lead to concerning symptoms.
Meningiomas can grow in different areas of the brain. Subtypes are based on where the tumor is located, including:
- Cavernous sinus: At the base of the skull where a number of critical structures including the carotid arteries which supply most of the blood to the brain and cranial nerves responsible for eye movements and facial sensation are located.
- Cerebellopontine angle: Near the margin of the cerebellum and the brainstem where critical nerves for face sensation, face movement, and hearing are located.
- Cerebral convexity: On the upper surface of the cerebral convexity.
- Foramen magnum: Close to the opening at the base of the skull, where the lower part of the brainstem becomes the spinal cord.
- Intraorbital: In or around the eye sockets.
- Intraventricular: In the fluid chambers that make and carry cerebrospinal fluid throughout the brain.
- Olfactory groove: On the nerves connect the brain to the nose.
- Parasagittal/falx: Next to the dural fold that divides the two brain hemispheres.
- Petrous ridge: In the bones at the base of the skull.
- Posterior fossa: Close to the back of the brain.
- Sphenoid: Near the sphenoid bone behind the eyes.
- Spinal: In the spine or against the spinal cord.
- Suprasellar: Near the pituitary gland in the skull.
- Tentorium: In the tentorium cerebelli, where the brain connects to the brain stem.