A slow-growing tumor of the meninges, occurring most often in adults.
[Short for meningothelioma : MENINGO- + (ENDO)THELIOMA.]
meningioma
Dictionary:
me·nin·gi·o·ma (mə-nĭn'jē-ō'mə)  |
n., pl., -mas, or -ma·ta (-mə-tə).
A slow-growing tumor of the meninges, occurring most often in adults.
A slow-growing tumor of the meninges, occurring most often in adults.
| 5min Related Video: meningioma |
| Oncology Encyclopedia: Meningioma |
Key Terms: Benign tumor, Computed tomography (CT) scan, Magnetic resonance imaging, Meninges, Neurofibromatosis.
Definition
A meningioma is a benign tumor of the central nervous system that develops from cells of the meninges, the membranes that cover and protect the brain and spinal cord.
Description
The Meninges
The delicate tissues of the brain and spinal cord are protected by a layer of bone and an inner covering called the meninges. The meninges are composed of three layers:
- dura mater
- arachnoid
- pia mater
The tough, thick dura mater forms the outer layer of the meninges and is attached to the bone of the skull and spinal cord. The arachnoid and pia mater layers are thinner and more delicate than the dura mater. The innermost pia mater layer is attached directly to the brain and spinal cord. Meningiomas arise from the middle arachnoid layer, and most remain attached to the dura mater by a dural tail.
Types of Meningiomas
Meningiomas account for 15–20% of all brain tumors, and 25% of all spinal cord tumors. The World Health Organization (WHO) classifies meningiomas into 11 different categories according to their cell type. However, because there are so many different cell types and so much overlap between types, meningiomas are most often placed into three general categories, including benign, atypical, and malignant.
Benign meningiomas are by far the most common, accounting for more than 90% of all meningiomas. These tumors grow slowly and produce symptoms only if they become large enough to compress nearby brain tissue. In some patients, meningiomas can grow very large with almost no symptoms. This happens because the tumor has grown very slowly and has gradually compressed the brain over time. Meningiomas can also cause fluid to build up in the brain, and can sometimes block veins. They may also grow into nearby bone, causing the bone to become thicker.
Up to 7% of meningiomas are classified as atypical. These tumors grow more quickly than benign meningiomas and are more likely to be symptomatic. Malignant meningiomas are fast-growing aggressive tumors and are the most rare, accounting for only about 2% of all meningiomas. It is extremely unusual for meningiomas to metastasize to other organs. When they do, the lungs are the most common site.
Only about one tenth of meningiomas are found in the spine. These slow-growing tumors cause symptoms when they begin to compress the spinal cord. Spinal meningiomas usually grow in the spinal canal between the neck and the abdomen, and are almost always benign.
Demographics
Only one person in every 50,000 is diagnosed with a symptomatic meningioma annually. Most of these patients are women. Women develop brain meningiomas almost twice as often as men and spinal meningiomas four to five times more often than men. The disease usually strikes middle-aged and elderly patients. Men are most affected between the ages of 50 and 60 years, while women are most affected between the ages of 60 and 70 years. Atypical and malignant meningiomas are more common in men. Meningiomas do not occur very often in children.
Causes and Symptoms
Causes
Although no single factor has been found that causes meningiomas, several risk factors are known. Some patients have developed a meningioma after being exposed to radiation. These patients tend to be younger than typical meningioma patients, and their tumors often grow more quickly. According to one study, the average age of patients with radiation-induced meningiomas is 38 years.
There is also a genetic component to meningioma. Patients who suffer from neurofibromatosis, a rare genetic disease, often develop multiple meningiomas.
Since meningioma cells recognize the female sex hormone progesterone, some researchers believe that female sex hormones may play a role in the development of meningiomas. This possible link is still being investigated.
A group of researchers at the National Cancer Institute reported in 2004 that people in certain occupations have a higher than normal risk of developing meningiomas. These higher-risk occupations include auto body painting, industrial production supervision, teaching, business management, interior decorating and design, and career military service. Further research is needed to determine whether there is a common causal factor linking these different fields of work.
Symptoms
Up to 75% of meningiomas produce no symptoms because they grow slowly and remain small. Often, tumors are discovered only when patients are being investigated for an unrelated illness. When symptoms do appear, it results that the tumor has grown large enough to compress part of the brain or spinal cord.
Patients experience different symptoms depending on the location of the tumor. Most brain meningiomas are located either just below the top of the skull, or between the two hemispheres of the brain. If the tumor is located in these areas, symptoms include:
- headaches
- seizures
- dizziness
- problems with memory
- behavior changes
- protrusion of one or both eyeballs (exophthalmos)
More rarely, tumors are near sensory areas of the brain such as the optic nerve or close to the ears. Patients with these tumors experience vision or hearing losses.
Spinal meningiomas are usually found in the spinal column between the neck and the abdomen. The most common symptoms are:
- pain
- weakness and stiffness of the arms and legs
- episodes of partial paralysis
Diagnosis
Meningiomas are diagnosed using a painless noninvasive technique called magnetic resonance imaging (MRI). MRI works by exposing the patient to harmless radio waves and a magnetic field, which produce clear images of the brain and the spine that show the size and location of tumors. No special preparation is required for the test.
Diagnosis can also be made by computed tomography (CT) scan. The CT scan uses low-dose x rays to generate a picture of the inside of the body. Sometimes a dye is injected into the patient's vein to improve the visibility of tissues. If the meningioma has grown into nearby bone, a CT scan will show the extent of bone invasion better than MRI. Women who are pregnant, or who think they might be pregnant, should tell their doctors before having a CT scan.
Treatment Team
The treatment team for a patient with a symptomatic meningioma may include a radiologist, a neurologist (specialist of the nervous system), and a neurosurgeon.
If surgery is necessary, a neurosurgeon will perform the procedure with the help of a surgical team. The team includes two or three nurses, and an anesthesiologist.
A small number of patients receive radiotherapy for their meningioma either because the tumor is too difficult to remove surgically, or because the surgeon had to leave some tumor behind. These patients will be referred to a radiation oncologist (specialist in giving radiation to cancer patients).
Clinical Staging, Treatments, and Prognosis
Staging
Meningiomas are classified into three different grades depending upon the likelihood of recurrence and aggressive growth:
- Grade I: Low risk of recurrence and slow growth
- Grade II: Greater likelihood of recurrence and/or aggressive growth
- Grade III: High recurrence rates and aggressive growth.
The vast majority of meningiomas are grade I. Atypical tumors are grade II, and malignant tumors are grade III.
Medical Therapies
Medical treatment for meningiomas is necessary when tumors cause symptoms. Fortunately, only about a quarter of meningiomas become symptomatic. Most patients are cured by surgery.
The objective of surgery is to remove not only the entire meningioma, but also the tail that attaches the tumor to the meninges. If the tumor has grown into bone, the bone is removed, too. If the tumor is in a difficult location in the brain, the surgeon may leave some tumor behind in order to preserve brain tissue.
The prognosis following brain meningioma treatment is very good. For the few patients who are not cured, prognosis depends on how completely the tumor is removed. If some tumor is left behind, recurrence is more likely, particularly for patients with grade II or grade III meningiomas. Ten years after surgery, 7–20% of patients with benign grade I tumors have a recurrence. For patients with malignant grade III tumors, up to 78% have a recurrence. A second surgery is sometimes necessary for patients with recurrent tumors.
Spinal meningioma is the most successfully treated meningioma, and the most successfully treated of all spinal tumors. Most of these tumors are removed completely, and they rarely recur. Even patients with quite severe symptoms fully recover after surgery.
For the few patients who are inoperable (usually because of tumor location), radiation therapy can stop the growth of tumors. Recently, stereotactic radiosurgery has been successfully used. This procedure uses images of the patient's skull to construct a frame that allows precise aiming of radiation, thus minimizing harm to nearby healthy tissue. Another option is fractionated radiotherapy, which also delivers precise doses of radiation to very small areas of tissue.
Not every patient with a meningioma receives surgery or radiation. Asymptomatic patients with small or slow-growing tumors can receive periodic MRI tests to check tumor growth. Treatment may also not be necessary for patients with mild or minimal symptoms.
Alternative and Complementary Therapies
Unlike many other cancers, conventional medical treatment of meningioma has very high success rates. As a result, alternative therapies are not commonly used for these tumors.
Coping With Cancer Treatment
When first diagnosed with a meningioma, many patients experience anxiety, resulting in nervousness, sleepless nights, and even nausea. However, patients can often relieve many of their fears by learning more about the disease and its course of treatment. Nevertheless, about 21% of patients with meningiomas develop psychiatric disorders, most commonly depression or an anxiety disorder.
The majority of meningioma patients are treated with surgery alone. Surgery will involve a hospital stay of at least a week. Before going home, patients are usually given medications to help prevent pain and swelling. Once home, patients can expect to feel some headache pain, and will become tired easily. If headaches and weakness become worse, a doctor should be contacted. Patients should make sure they get plenty of rest and eat a balanced, nutritious diet. Most patients can begin to resume their normal activities in about six to eight weeks.
Clinical Trials
Chemotherapy is seldom given to meningioma patients because surgery (and/or radiotherapy) is usually successful. For patients with tumors that do not respond to these treatments, however, chemotherapy is available within a clinical trial.
Clinical trials have investigated several drugs to treat patients whose meningioma recurs following failure of both surgery and radiotherapy. Hydroxyurea, a drug used to treat some other cancers, has been shown to slow the growth of meningioma cells. Studies of hydroxyurea continue. Some trials have explored the link between meningioma and female sex hormones. Tamoxifen, an anti-estrogen drug used to fight breast cancer, has produced disappointing results. Trials using RU-486, an anti-progesterone agent, are underway. Information on these and other open clinical trials is available on the Internet from the National Cancer Institute at
Prevention
The most avoidable risk factor for the development of meningioma is exposure to radiation. Children exposed to small amounts of radiation in the 1950s to treat tinea captis, a fungal infection of the scalp, developed meningiomas at an unusually high rate. There is also a clear relationship between radiation dose and meningioma: the higher the radiation dose, the greater the probability of developing a meningioma.
Special Concerns
The Very Elderly
In very elderly people, the symptoms of a meningioma can be very similar to normal aging. These patients typically experience difficulty with learning and remembering things as a result of the tumor. Headaches, a classic symptom of a meningioma, are not usually reported. Treatment of very elderly patients may be difficult if the patient is too frail for surgery.
Children
On the rare occasions that meningiomas are diagnosed in children, they tend to be large, fast growing, and located in unusual positions. Treatment for children is the same as for adults: complete tumor removal with surgery and/or radiotherapy.
Questions to Ask the Doctor
- Will I need to have surgery?
- Can I expect a full recovery after surgery?
- Will I need radiotherapy?
- How often will I need to return for an MRI or CT scan?
- How soon can I return to work after surgery?
Neurofibromatosis
Neurofibromatosis (NF) is actually two different genetic diseases: NF Type 1 and NF Type 2. NF Type 2 is the more rare of the two diseases, affecting only one in 40,000 individuals. These patients often develop multiple brain meningiomas. Although there is no cure for NF, meningioma tumors can be removed with surgery.
Resources
Books
Beers, Mark H., MD, and Robert Berkow, MD, editors. "Exophthalmos." Section 8, Chapter 92 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.
Beers, Mark H., MD, and Robert Berkow, MD, editors. "Intracranial Neoplasms (Brain Tumors)." Section 14, Chapter 177 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.
Greenberg, Harry S., et al., editors. Brain Tumors. New York: Oxford University Press, 1999.
Kleihues, Paul, and Webster K. Cavenee, editors. World Health Organization Classification of Tumours: Tumours of the Nervous System. Lyon: IARC Press, 2000.
Periodicals
Al-Mefty, O., C. Topsakal, S. Pravdenkova, et al. "Radiation-Induced Meningiomas: Clinical, Pathological, Cytokinetic, and Cytogenetic Characteristics." Journal of Neurosurgery 100 (June 2004): 1002–1013.
DeAngelis, Lisa M. "Brain Tumors." New England Journal of Medicine 344, no. 2 (January 11, 2001): 114–23.
Drummond, K. J., J. J. Zhu, and P. M. Black. "Meningiomas: Updating Basic Science, Management, and Outcome." Neurologist 10 (May 2004): 113–130.
Gupta, R. K., and R. Kumar. "Benign Brain Tumours and Psychiatric Morbidity: A 5-Years Retrospective Data Analysis." Australian and New Zealand Journal of Psychiatry 38 (May 2004): 316–319.
Rajaraman, P., A. J. De Roos, P. A. Stewart, et al. "Occupation and Risk of Meningioma and Acoustic Neuroma in the United States." American Journal of Industrial Medicine 45 (May 2004): 395–407.
Yamasaki, Fumiyuki, et al. "Recurrence of Meningiomas." Cancer 89, no. 5 (September 1, 2000): 1102–1110.
Organizations
American Brain Tumor Association. 2720 River Road, Des Plaines, IL 60018. (800) 886-2282.
The Brain Tumor Society. 124 Watertown Street, Suite 3-H, Watertown, MA 02472. (800) 770-8287.
The Johns Hopkins Meningioma Society. Johns Hopkins University. Harvey 811, 600 North Wolfe Street, Baltimore, MD 21205-8811. (410) 614-2886.
National Brain Tumor Foundation. 414 Thirteenth Street, Suite 700, Oakland, CA 94612-2603. (800) 934-2873.
National Cancer Institute (National Institutes of Health). 9000 Rockville Pike, Bethesda, MD 20892. (800) 422-6237.
—Alison McTavish, M.Sc.; Rebecca J. Frey, Ph.D.
| Dental Dictionary: meningioma |
n
A mesenchymal fibroblastic tumor of the membranes enveloping the brain and spinal cord. Meningiomas grow slowly, are usually vascular, and occur most commonly near the superior longitudinal, transverse, and cavernous sinuses of the dura mater of the brain.
| Veterinary Dictionary: meningioma |
A common, well-defined, firm intracranial neoplasm of animals arising from leptomeningeal cells, which occurs in basal locations, over the cerebral, cerebellar convexities, and in the spinal cord. One subtype is characterized by psammoma bodies (central calcified material).
- angioblastic m. — angioblastoma.
- epithelioid m. — see meningotheliomatous meningioma (below).
- meningotheliomatous m. — a diffusely cellular mesodermal tumor with cells in sheets or in pseudoalveoli.
| Wikipedia: Meningioma |
| Meningioma | |
|---|---|
| Classification and external resources | |
 A contrast enhanced CT scan of the brain, demonstrating the appearance of a Meningioma. |
|
| ICD-10 | C70, D32 |
| ICD-9 | 225.2 |
| ICD-O: | M9530/0 |
| OMIM | 607174 |
| DiseasesDB | 8008 |
| eMedicine | neuro/209 radio/439 |
| MeSH | D008579 |
Meningiomas are the second most common primary tumor of the central nervous system, arising from the arachnoid "cap" cells of the arachnoid villi in the meninges.[1] These tumors are usually benign in nature; however, they can be malignant.[2]
Contents |
Causes
Most cases are sporadic while some are familial. Persons who have undergone radiation to the scalp are more at risk for developing meningiomas.[3]
The most frequent genetic mutations involved in meningiomas are inactivation mutations in the neurofibromatosis 2 gene (merlin) on chromosome 22q.
Other possible genes/loci include:
Signs and symptoms
Main article: brain tumor
Small tumors (e.g., < 2.0 cm) are usually incidental findings at autopsy without having caused symptoms. Larger tumors can cause symptoms depending on the size and location.
- Focal seizures may be caused by meningiomas that overlie the cerebrum
- Progressive spastic weakness in legs and incontinence may be caused by tumors that overlie the parasagittal frontoparietal region.
- Sylvian tumors may cause myriad motor, sensory, aphasic, and seizure symptoms depending on the location.
- Increased intracranial pressure eventually occurs, but is less frequent than in gliomas.
Mechanism
Meningiomas arise from arachnoidal cells,[7] most of which are near the vicinity of the venous sinuses, and this is the site of greatest prevalence for meningioma formation. They are most frequently attached to the dura over the superior parasagittal surface of frontal and parietal lobes, along the sphenoid ridge, in the olfactory grooves, the sylvian region, superior cerebellum along the falx cerebri, cerebellopontine angle, and the spinal cord. The tumor is usually gray, well-circumscribed, and takes on the form of space it occupies. They are usually dome-shaped, with the base lying on the dura.
Histologically, the cells are relatively uniform, with a tendency to encircle one another, forming whorls and psammoma bodies (laminated calcific concretions).[8] They have a tendency to calcify and are highly vascularized.
Diagnosis
Meningiomas are readily visualized with contrast CT, MRI with gadolinium, and arteriography, all attributed to the fact that meningiomas are extra-axial and vascularized. CSF protein is usually elevated if lumbar puncture is attempted.
Though the majority of meningiomas are benign, they can have malignant presentations. Classification of meningiomas are based upon the WHO classification system. [9]
- Benign (Grade I) - (90%) - meningothelial, fibrous, transitional, psammomatous, angioblastic (most aggressive)
- Atypical (Grade II) - (7%) - choroid, clear cell, atypical
- Anaplastic/malignant (Grade III) - (2%) - papillary, rhabdoid, anaplastic
In a recent retrospective review of atypical and anaplastic meningioma cases, it was found that the mean overall survival for atypical meningiomas was 11.9 years vs. 3.3 years for anaplastic meningiomas. Mean relapse free survival for atypical meningiomas was 11.5 years vs. 2.7 years for anaplastic meningiomas.[10]
Treatment
Observation
Observation with close imaging follow-up can be used in select cases if a meningioma is small and asymptomatic. In a retrospective study on 43 patients, it was found that 63% of patients had no growth on follow-up, and the 37% found to have growth grew at an average of 4 mm / year.[11] In this study, younger patients were found to have tumors that were more likely to grow on repeat imaging, thus are poorer candidates for Observation.
Observation is not recommended in tumors that are already causing symptoms. Furthermore, close follow-up with imaging is required with an Observation strategy to rule out an enlarging tumor.[12]
Surgical resection
Meningiomas can usually be surgically resected with permanent cure if the tumor is superficial on the dural surface and easily accessible. Transarterial embolization has become a standard preoperative procedure in the preoperative management.[13] If invasion of the adjacent bone occurs, total removal is nearly impossible. Malignant transformation is rare.
The probability of tumor recurrence or growth after surgical resection can be estimated by the tumor's WHO Grade and by the extent of surgery by the Simpson Criteria.[14]
| Simpson Grade | Completeness of Resection | 10-year Recurrence |
|---|---|---|
| Grade I | complete removal including resection of underlying bone and associated dura | 9% |
| Grade II | complete removal + coagulation of dural attachment | 19% |
| Grade III | complete removal w/o resection of dura or coagulation | 29% |
| Grade IV | subtotal resection | 40% |
Radiation therapy
Radiation therapy may include Gamma Knife, proton beam treatment, or fractionated external beam radiation. Gamma Knife radiosurgery can be used in lieu of surgery in small tumors located away from critical structures.[15] Fractionated external beam radiation can also be used as primary treatment for tumors that are surgically unresectable, or for patients who are inoperable for medical reasons.
Radiation therapy is often considered for WHO Grade I meningiomas after subtotal (incomplete) tumor resections. The clinical decision to irradiate after a subtotal resection is somewhat controversial as no class I randomized controlled trials exists on the subject.[16] Numerous retrospective studies, however, have strongly suggested that the addition of post-operative radiation to incomplete resections improves both progression free survival (i.e. prevents tumor recurrence) and improves overall survival.[17]
In the case of a Grade II or Grade III meningioma, the current standard of care involves post-operative radiation treatment regardless of the degree of surgical resection.[18] This is due to the proportionally higher rate of local recurrence for these higher grade tumors.
Conventional chemotherapy
Current chemotherapies are likely not effective. Antiprogestin agents have been used, but with variable results.[19] Recent evidence that hydroxyurea has the capacity to shrink unresectable or recurrent meningiomas is being further evaluated.[20]
See also
References
- ^ Buetow MP, Buetow PC, Smirniotopoulos JG (November 1991). "Typical, atypical, and misleading features in meningioma". Radiographics 11 (6): 1087–106. PMID 1749851. http://radiographics.rsnajnls.org/cgi/pmidlookup?view=long&pmid=1749851. Retrieved 2008-12-01.
- ^ Goldsmith BJ, Wara WM, Wilson CB, Larson DA (February 1994). "Postoperative irradiation for subtotally resected meningiomas. A retrospective analysis of 140 patients treated from 1967 to 1990". J. Neurosurg. 80 (2): 195–201. PMID 8283256.
- ^ Rabin BM (September 1996). "Radiation-induced changes in the central nervous system and head and neck". Radiographics 16 (5): 1055–72. PMID 8888390. http://radiographics.rsnajnls.org/cgi/reprint/16/5/1055.
- ^ Lekanne Deprez RH, Riegman PH, Groen NA, et al. (April 1995). "Cloning and characterization of MN1, a gene from chromosome 22q11, which is disrupted by a balanced translocation in a meningioma". Oncogene 10 (8): 1521–8. PMID 7731706.
- ^ Staal FJ, van der Luijt RB, Baert MR, et al. (May 2002). "A novel germline mutation of PTEN associated with brain tumours of multiple lineages". Br. J. Cancer 86 (10): 1586–91. doi:. PMID 12085208.
- ^ Zattara-Cannoni H, Roll P, Figarella-Branger D, et al. (April 2001). "Cytogenetic study of six cases of radiation-induced meningiomas". Cancer Genet. Cytogenet. 126 (2): 81–4. PMID 11376799. http://linkinghub.elsevier.com/retrieve/pii/S0165-4608(00)00398-8.
- ^ "moon.ouhsc.edu". http://moon.ouhsc.edu/kfung/jty1/Com/Com306-1-Diss.htm. Retrieved 2008-11-30.
- ^ "Neuropathology For Medical Students". http://www.pathology.vcu.edu/WirSelfInst/neuro_medStudents/tumor-1.html. Retrieved 2008-11-30.
- ^ Wrobel G, Roerig P, Kokocinski F, et al. (March 2005). "Microarray-based gene expression profiling of benign, atypical and anaplastic meningiomas identifies novel genes associated with meningioma progression". Int. J. Cancer 114 (2): 249–56. doi:. PMID 15540215. http://dx.doi.org/10.1002/ijc.20733.
- ^ Yang SY et al.: Atypical and anaplastic meningiomas: prognostic implications of clinicopathological features. J Neurol Neurosurg Psychiatry. 2008 May;79(5):574-80. Epub 2007 Aug 31.
- ^ Herscovici Z, et al.: Natural history of conservatively treated meningiomas." Neurology. 2004 Sep 28;63(6):1133-4.
- ^ Olivero WC et al.: "The natural history and growth rate of asymptomatic meningiomas: a review of 60 patients." J Neurosurg. 1995 Aug;83(2):222-4
- ^ [1]
- ^ Simpson D. "The recurrence of intracranial meningiomas after surgical treatment." J Neurol Neurosurg Psychiatry. 1957 Feb;20(1):22-39.
- ^ Kullova A et al.: Gamma Knife surgery for benign meningioma. J Neurosurg. 2007 Aug;107(2):325-36.
- ^ Taylor BW et al.: The meningioma controversy: postoperative radiation therapy. Int J Radiat Oncol Biol Phys. 1988 Aug;15(2):299-304.
- ^ Goldsmith BJ et al.: Postoperative irradiation for subtotally resected meningiomas. A retrospective analysis of 140 patients treated from 1967 to 1990. J Neurosurg. 1994 Feb;80(2):195-201.
- ^ Goyal LK et al. "Local control and overall survival in atypical meningioma: a retrospective study," Int J Radiat Oncol Biol Phys. 2000 Jan 1;46(1):57-61.
- ^ Wahab M et al.: Meningioma and hormonal influences. Climacteric. 2003 Dec;6(4):285-92.
- ^ Newton HB. Hydroxyurea chemotherapy in the treatment of meningiomas. Neurosurg Focus. 2007;23(4):E11.
External links
- Meningioma Information from the American Brain Tumor Association
- Meningioma information from the Mayo Clinic
- MR/CT scans of meningioma from MedPix
- CancerBackup
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