About the central nervous system
The brain and spinal column make up the central nervous system (CNS), where all vital functions of the body are controlled. When a tumor forms in the CNS, it can be especially problematic and challenging to treat because a person’s thought processes and movements can be affected.
A tumor begins when healthy cells change and grow uncontrollably, forming a mass. A tumor can be cancerous or benign. A cancerous tumor is malignant, meaning it can grow and spread to other parts of the body. A benign tumor means the tumor can grow but will not spread.
This guide focuses on meningioma, which is a slow-growing tumor that usually forms on the surface of the brain and may cause significant symptoms if it grows and presses on the brain or spinal cord. Specifically, meningioma is a type of tumor that occurs in the meninges, which are the thin membranes that surround and protect the brain and spinal cord. There are three meningeal layers called the dura mater, arachnoid, and pia mater. The cerebrospinal fluid (CSF) is made near the center of the brain, in the lateral ventricles, and circulates around the brain and spinal cord between the arachnoid and pia layers.
Approximately 80% of meningiomas are benign. The remaining 20% are either called atypical with an increased risk of recurrence or, rarely, malignant.
Subtypes of meningioma
Meningioma can be divided based on where it starts in the CNS.
Falx and parasagittal meningioma. The falx is a membrane sitting in a groove that runs between the two sides of the brain. It contains a large blood vessel. Parasagittal meningioma occurs near the falx. These are the most common types, making up about 25% of all meningiomas.
Convexity meningioma. This type of meningioma occurs on the upper surface of the brain and makes up about 20% of meningiomas.
Sphenoid meningioma. The sphenoidal ridge is located behind the eyes. Sphenoid meningioma occurs mostly in women. This type of meningioma makes up 20% of all meningiomas.
Olfactory groove meningioma. This type of meningioma occurs along the nerves that connect the brain to the nose and makes up 10% of meningiomas.
Posterior fossa meningioma. Posterior fossa meningioma develops at the back of the brain, on the underside, and makes up 10% of all meningiomas.
Suprasellar meningioma. Suprasellar meningioma occurs next to the sella turcica, an area at the base of the skull where the pituitary gland sits. This type makes up 10% of all meningiomas.
Spinal meningioma. Most common in women between the ages of 40 and 70, a spinal meningioma usually occurs in the spine at chest level and may push against the spinal cord. Spinal meningioma may cause pain radiating around the chest wall, bladder trouble, and/or weakness or numbness in the legs. This type makes up less than 10% of all meningiomas.
Intraorbital meningioma. This type of meningioma develops in or around the eye sockets, and accounts for less than 10% of meningiomas.
Intraventricular meningioma. Intraventricular meningioma occurs in the chambers that carry fluid throughout the brain, and makes up about 2% of all meningiomas.
Looking for More of an Overview?
If you would like additional introductory information, explore this related item. Please note this link will take you to another section on Cancer.Net:
- Cancer.Net Patient Education Video: View a short video on brain tumors led by an ASCO expert that provides basic information and areas of research.
The next section in this guide is Statistics and it helps explain how many people are diagnosed with this disease and general survival rates. Or, use the menu on the side of your screen to choose another section to continue reading this guide.