A meningioma is a mass that originates in the meninges, a membranous layer covering the central nervous system (CNS).
These tumors are the second most common type of neoplasm in the CNS. Although they are almost always benign, some do become malignant. Patients who have undergone radiation in the past are at a greater risk of developing a meningioma.
Signs & Symptoms
Smaller masses usually do not cause any symptoms. As the mass gets larger, it may present any of the following symptoms:
- Focal seizures that only affect part of the brain
- Spastic weakness in the legs that may worsen
- Motor, sensory, or seizure symptoms caused by sylvian tumors
- Intense intercranial pressure
Diagnosis & Treatment
Meningiomas are easily detectable with a CT or CAT scan, MRI, or x-ray, all of which will clearly show the size and location of the mass (an MRI, in particular, can also print a detailed image of the mass to be examined at a later date). A biopsy, in which a small piece of the mass’ tissue is cut away and examined under a microscope, can provide a definitive diagnosis as to whether the mass is benign or malignant.
Meningiomas are classified into one of three categories:
- Benign—90% of these tumors are benign, although they are the most aggressive form
- Atypical—7%; these masses invade the brain and affect the body’s motor skills
- Anaplastic/malignant—2%; these masses are highly aggressive and metastasize (spread) at a very rapid rate
Treatment for a meningioma depends on its size and location. If the mass is very small, a patient’s physician may simply observe it to note any change in appearance or the patient’s overall health. A very small percentage of observed patients developed symptoms.
If the patient has already started developing symptoms, more intense treatment is recommended. If the mass is easily accessible, it can usually be surgically resected or removed. If the tumor is more difficult to access, it may be treated with pinpoint beams of radiation. Most traditional chemotherapy treatments have found to be ineffective.
A patient’s prognosis depends on the size, location, and stage of the mass. The average survival rate for patients with atypical meningiomas is 11.9 years; 3.3 for anaplastic/malignant.