What Is It?
A meningioma is one of the most common primary brain tumors. It is almost always a benign tumor that arises from cells of the arachnoid membrane.
The arachnoid membrane is one of the three layers covering the brain and spinal cord. It is a thin, filmy, spider web-like tissue (hence the name arachnoid, or "spider web-like"). Therefore, these tumors actually arise outside the brain itself, but because of their close proximity to nervous system structures, they are often touching or pushing into parts of the brain or spinal cord. They can occur anywhere where arachnoid is found, throughout the intracranial compartment and the spinal column. Rarely they can be found inside the cerebral ventricles, the fluid spaces within the brain.
While the large majority of meningiomas are benign and very slow growing, rarely they can have more malignant pathology and therefore act more aggressively and invasively.
Most meningiomas are named for their site of origin. For example, they can be classified as convexity, parafalcine, skull base, olfactory grove, tuberculum sellae, dorsum sella, clival, petrosal, cerebellopontine, foramen magnum or spinal, to name a few, all referring to various anatomical locations around the central nervous system.
What Types of Symptoms Are Typical?
When small, most meningioma are asymptomatic. Depending on their location, as they enlarge, they can start to invade or cause compression of neurological structures. As this happens, symptoms related to that neurological structure can occur. Typically this progression is slow as most of these tumors grow slowly over years or decades.
Neurological symptoms depend completely on the location of the tumor. Large convexity tumors may cause weakness or sensory symptoms on the opposite side of the body. Large frontal or temporal tumors sometimes cause psychological disturbances, including personality changes. Tumors of the skull base can affect the function of cranial nerves, producing problems with smell, vision, hearing and balance, facial movement, facial sensation, swallowing, and eye movements, to name just a few possibilities.
In addition to these symptoms which are specific to the location of a given tumor, headache is a common finding in many of these patients. Seizure can also occur, particularly with tumors that compress parts of the cerebral cortex.
How Is The Diagnosis Typically Made?
After presenting for a neurological examination, generally a CT scan
or MRI scan
will reveal the tumor. Meningiomas have a very characteristic appearance but they can be mistaken for other tumors depending on their location. Therefore, like most other tumors, a piece of tumor tissue is needed to make a definitive diagnosis. This is usually accomplished through surgery or a biopsy.
What Are Some Common Treatments?
The treatment plan for these tumors varies considerably from patient to patient, depending on symptoms, and location and size of the tumor. Asymptomatic tumors may be watched closely unless the patient prefers early surgery. In the case of symptomatic tumors, surgery to remove or de-bulk the tumor is often recommended. The specific surgical approach varies depending on the tumor size and location. The goal of surgery is to remove the entire tumor, which gives the best chance for a cure or long-term control. However, in some locations complete removal is not possible or risky and therefore some tumor is left.
Radiation treatments, particularly focused beam radiation or stereotactic radiation treatments, are also sometimes used. They are often effective at slowing or stopping the growth of the tumor, although some continue to grow or do not decrease in size. This is frequently used for any residual tumor which is left after surgery to delay or prevent its re-growth.
As with all medical conditions, the appropriate treatment plan varies from patient to patient dependent on many factors. Each patient should discus their individual case and their options with their physician team.
Return to the Brain Tumor page from the Meningioma page.
Return to the Nervous System Diseases home page.
This site is not intended to offer medical advice. Every patient is different, and only your personal physician can help to counsel you about what is best for your situation. What we offer is general reference information about various disorders and treatments for your education.