- Meningiomas are tumors that grow on the delicate outer covering of the brain. This covering is called the meninges.
- Meningiomas account for approximately 30.1% of all primary brain tumors, making them the most common type. This number is probably low as some meningiomas may never be diagnosed. Two percent of routine autopsies reveal undiagnosed primary brain tumors.
- Meningiomas account for approximately 20% of all intracranial tumors in males and 38% in females.
- The prevalence of meningioma is estimated to be approximately 97.5 in 100,000 in the United States with over 138,000 individuals currently diagnosed with this tumor.
- The Central Brain Tumor Registries of the United States predict that within the U.S. over 11,000 new cases of meningioma will be diagnosed.
- This type of primary brain tumors grow slowly in the brain and usually do not spread to other parts of the body.
- Meningiomas can grow anywhere on the meninges and as a result can affect sensory (sight, hearing, touch) and cognitive (memory, judgment) functioning.
- Meningiomas often do not cause symptoms until the tumor is quite large. Symptoms of meningiomas are the result of the tumor compressing parts of the brain. Types of symptoms that patients with meningiomas experience include: headache, vision problems, behavioral changes, and seizures. A patient may have subtle symptoms for a long period of time before the meningioma is diagnosed.
- Meningiomas may be categorized as benign (>90%), atypical/borderline (5%) and malignant (3-5%). Within the benign category, there are several subtypes: syncytial, fibrous and transitional. With the exception of malignant meningioma, these classifications are imprecise with respect to prediction of patient outcome or response to treatment.
- Meningiomas occur most often between the ages of 40 and 70 years. Meningiomas are rare in children and only 1.5% of all meninigomas occur in childhood and adolescence.
- Meningiomas are more common in women than in men, with 65% of all diagnosed meningiomas occurring in women.
- The cause of meningiomas is unknown. Risk factors for meningiomas include prior radiation exposure to the head, and a genetic disorder called neurofibromatosis type 2 (NF2), which affects the nervous system and the skin. Many patients with meningiomas have no risk factors.
- Surgery often is the best treatment option for meningioma. The location of the tumor may make surgery impossible or may prevent complete removal of the tumor. Other treatment options include radiation and radiosurgery, which is the precise delivery of radiation to the tumor using special procedures.
- Meningiomas can recur despite successful surgery. The recurrent tumor may be a faster growing, higher-grade tumor. Chemotherapy and biological agents are being studied for the treatment of recurrent meningiomas.
To read "Your Meningioma Diagnosis" (PDF), click here.
Medical content reviewed September 8, 2002 by Elizabeth Noll, Director of Neurosurgical Research Affairs, Brigham and Women's and Children's Hospital.
