A meningioma is the most common kind of benign brain tumor. Benign brain tumors, which seem to "strike out of the blue," can cause a range of problems, but they are treatable, says Dr. Joshua Bederson, Professor and Chairman of Neurosurgery, who oversees 500 benign brain tumor patients a year. "The initial diagnosis is terrifying, but it's important to keep in mind that we can get our patients through this."
A meningioma is a benign brain tumor that arises from the meninges, the membranes surrounding the brain and spinal cord. Approximately 30% of brain tumors are meningiomas, and 13,000 are diagnosed in North America each year. Bederson explains that "a benign brain tumor is a growth that arises from normal cells within the brain. Although the growth of these cells is uncontrolled, it is not rapid enough to qualify as a malignant brain tumor." If left untreated, these tumors can grow as large as a grapefruit. While most benign tumors manifest themselves in middle-aged patients, between the ages of 40 and 60, meningiomas are also found in the young and old. Women are affected more than men.
Detection and diagnosis of benign tumors
Because benign tumors tend to grow slowly, the patient may not notice any symptoms until they become severe. In the early stages, the tumors are easily misdiagnosed. "The patient says, I've got this funny headache; things don't taste right," explains Dr. Bederson, "and that can go on for months or years, until an MRI is done, and everyone is stunned to learn there is a tumor." In addition to the size of the benign tumor, the location of the tumor also determines the symptoms. Even a small tumor the size of a grape pressing on the optic nerve could cause visual loss while a tumor located in the convexity or on the surface of the brain may reach the size of a grapefruit before the patient notices any symptoms. Because we don't know how to prevent a tumor, awareness of minor symptoms is essential: early detection allows more treatment options before the tumor grows to a large size. Patients may experience persistent headaches and/ or nausea, both new and unusual, in addition to loss of neurological function. The latter can include numbness, weakness and tingling, especially on one side of the body. Seizures may occur. Symptoms depend on which nerves are affected: if endocrine output is affected, as with a pituitary adenoma, patients may experience irregular periods, abnormal lactation and abnormal growth. Other tumors may cause hearing or visual loss. To diagnose a tumor, Dr. Bederson advises the "Good communication with your doctor is key, so they know where to send you for an MRI."
It is important to treat benign tumors early so they don't cause disability. Three courses of treatment are observation, surgery and radiation. Because not all benign tumors need to be removed, the physician can watch the slow growing tumor as long as it does not affect cognitive function. A patient should ask the physician is conservative management is an option. If it is, the patient would have MRIs first every six months and eventually every year to monitor the growth of the tumor. If surgery is necessary, it is important to find a neurosurgeon and a surgical team experienced in all courses of treatment. The patient should ask if stereotactic radiosurgery is an option or if there are minimally invasive or endoscopic-assisted approaches to remove the tumor. Surgery and radiation may be used separately or in combination. Dr. Bederson explains, "The vast majority of benign tumors are permanently cured by simple and safe surgical removal. In certain cases when the tumor involves critical structures, we'll remove 90-99%, and we observe the rest. If the tumor begins to grow back, radiation can stop its growth."
Advances in Care
Dr. Bederson explains that "there are rapidly evolving surgical techniques that allow us to remove tumors through the nose," a technique that allows quicker recovery than if the head were opened. Also, with an operation using an endoscopic or minimally invasive technique, patients sometimes leave the hospital the day following the operation. The patient can be back at work the same day if he undergoes stereotactic radiosurgery, which usually requires a series of treatments. Not all approaches are suitable for every patient, so it is important to have a neurosurgeon who is familiar with and skilled in all treatment techniques.
The patient was a 44-year-old woman who had known about a small (walnut size) meningioma for two years. The lesion was diagnosed during a workup for vertigo and anxiety. Her anxiety did not change over time, and she had no other specific symptoms relating to the tumor except possibly headaches. Serial MRIs confirmed that the tumor had grown slowly; the surrounding edema on the left side had also increased, and there was now edema on the right side. Thus, surgical resection was recommended.
A 62-year-old woman had an 8-cm meningioma that was discovered when she began to have a decrease in mental status and weakness on one side of her body. On MRI the lesion was seen to be dangerously close to the optic nerve. Because of swelling around the tumor, surgery became urgent. The patient recovered well after the surgery and continued to improve at home. At her post-op visit she was remarkably bright and alert with no focal motor deficits, although she still had some short-term memory problems.
Meet the team
Members of our meningioma team include:
Isabelle Germano, MD (radiosurgery)
Jane Walsh, NP
We can help
The team at Mount Sinai is experienced in all courses of treatment for brain tumors. For an appointment, call 212-241-2377.
Dr. Bederson and his work on treating meningiomas were recently profiled in The Daily News feature, The Daily Check Up. View the article.