A meningioma is a slow-growing tumor that develops on the meninges, the tough membrane that covers and protects the brain and the portion of the spinal cord that’s just inside the skull. Meningiomas are almost always benign, and they’re the most common type of tumor to form in the central nervous system (the brain and spinal cord). Atypical meningiomas are not considered benign or cancerous, but they may become cancerous (malignant) over time. The few meningiomas that are malignant tend to grow much more rapidly, sometimes spreading to other areas of the brain and the lungs. Although the underlying cause of meningiomas is not known, exposure to radiation is a risk factor. People with an inherited disorder called neurofibromatosis type 2 are also at greater risk. Meningiomas sometimes are found in areas where scarring or fractures have occurred. Meningiomas are more common among women than men, and a few studies suggest a link between meningioma formation and the hormone progesterone.
Meningiomas often cause no symptoms until and unless they grow large. When symptoms do occur, they can include:
Some symptoms depend on the location of the meningioma and which area of the brain it’s pressing on. Large meningiomas can be life-threatening.
Once a meningioma has been identified with diagnostic imaging such as an MRI or CT scan, a biopsy may be performed to obtain a small tissue sample to determine if the tumor is benign or malignant. Tumors that are not causing symptoms are usually observed with regular brain scans to monitor their growth. When tumors cause symptoms or when their growth threatens the patient’s health, surgery can be performed to remove the tumor or radiosurgery may be used to shrink or destroy the tumor with targeted radiation delivered through the skin without incisions. Radiation may also be used in combination with surgery when parts of the tumor cannot be surgically removed.