Meningioma - everything you’ll need to know

What is a Meningioma?

Meningiomas are one of the most common intracranial tumors that represent about one-third of all primary brain tumors, even though they do not arise from within the brain tissue itself. They tend to arise from the membranes that cover the brain and the spinal cord instead. These membranes are anatomically known as meninges, hence the term meningioma. Unlike some tumors, they are primarily benign rather than malignant (i.e., cancerous) and thus do not metastasize or spread to distant organs of the body.

Who is at Risk for a Meningioma?

The underlying cause for meningiomas is still unclear but researchers have identified some risk factors for it that can be understood under the following headings:

• Age & Gender Females with increasing age are mostly associated with meningiomas, especially with ages between 40 to 70 years.
• Exposure to radiation A higher incidence of meningiomas has been reported in patients with a broad history of exposure to ionizing radiations. Tumors that stem from these factors are also known to be more aggressive.
• Genetic predisposition Individuals with a mutation in the NF2 gene lead to a genetic disorder known as Neurofibromatosis type 2. Such individuals possess cells that can convert normal cells into cancerous cells, thus giving rise to meningiomas.
• Hormonal Fluctuations It is believed that certain hormones (like estrogen) play a role in the development of this brain tumor. This also explains why women are more likely to be affected with a meningioma than men. Some links between breast cancer and meningiomas have also been established
• Race and Ethnicity People with African ancestry have a higher chance of developing meningiomas compared to other race and ethnicities.
• Obesity High body mass indices or BMIs have been established risk factors for many types of cancers, and a higher prevalence is seen in meningiomas.

What does it look like, Signs & Symptoms?

Patients with meningioma might be completely asymptomatic or may complain of neurological symptoms based on the tumor’s location. According to the area of the brain that they involve, meningiomas can present as:

1. Impairment of reasoning and memory if the falx is affected.
2. Limb weakness or numbness if the frontal lobe is affected.
3. Seizures and/or headaches if they overlie the cerebrum.
4. Double vision or visual deficits if the sphenoid or optic nerve is affected.
5. Loss of smell if they overlie the olfactory groove.
6. Backaches if the spinal cord is affected.
7. A rise in the intracranial pressure can eventually occur.

What is the Classification of Meningiomas?

Grading meningiomas is necessary to come up with a specific treatment plan. The World Health Organization has formulated a three-tier system that determines the grading of a tumor based on tissue examined under a microscope. This is done based on several factors namely age, presence of genetic mutations, location and extent of tumor spread, and the possibility of surgery. Each grade is then divided into relevant subtypes:

• Grade I or benign meningioma are low-grade tumors that make up 90% of all meningiomas. They are usually asymptomatic and grow rather slowly.
• Grade II or atypical meningioma are mid-grade tumors and can recur even after surgical excision. They are symptomatic, grow more quickly and subtypes include choroid and clear cell meningiomas.
• Grade III or anaplastic meningioma are high-grade tumors that account for only 2% of the overall count. They are aggressive, malignant, and the fastest growing of the lot. Subtypes include the papillary and rhabdoid type and complete surgical excision is usually the treatment of choice.

What Tests are used in Diagnosing them?

The first step pertaining to the diagnosis-making of a patient with meningioma is the bedside neurological exam. Although imaging is a much better modality to solidify the diagnosis of a meningioma, a neurological exam is vital to rule out other differentials. For this exam, the healthcare professional might ask questions regarding the patient's symptoms that include, visual and hearing deficits, balance & coordination, complaints of seizures or headaches, back pain, and/or mental status.

Once signs related to the tumor are caught, the patient is sent to imaging as the second modality of non-invasive testing. The presence of a tumor can pretty much be confirmed via a CT (computed tomography or MRI (magnetic resonance imaging) scan. Lastly, when a mass is detected within the brain, the healthcare provider may also suggest a more invasive procedure called the biopsy where a sample of the affected tissue is removed to be examined under a microscope.

What are your Treatment Options?

Multiple factors determine the mode of management where meningiomas are concerned. Apart from the obvious, location, size, growth rate, and symptoms it must be appreciated that not all meningiomas are to be treated right away. Patients must also never refrain from taking second opinions as it helps in the betterment of the original treatment plan. The decision of how best to treat meningiomas falls upon the following basic options:

What are your Treatment Options?

Multiple factors determine the mode of management where meningiomas are concerned. Apart from the obvious, location, size, growth rate, and symptoms it must be appreciated that not all meningiomas are to be treated right away. Patients must also never refrain from taking second opinions as it helps in the betterment of the original treatment plan. The decision of how best to treat meningiomas falls upon the following basic options:

Observation
Some select cases of meningioma that are characterized by slow-growing, small tumors with mild & minimal symptoms that barely affect the patient's quality of life are best left under observation. This management option is better suited for older individuals with symptoms that are very slowly progressive. Over a period, observation can help determine a more appropriate course of action.

Surgery
It can be said that complete surgical excision is the best way to be cured of a meningioma. The first and foremost priority in this situation though is to preserve the individual's neurological function or improve the deficit. However, the primary goal is still to remove the unwanted tissue completely including the fibers that attach it to the coverings of the brain and bone, without any complications. Despite that, no surgery comes forth with its potential risk, especially if the meningioma has invaded into the adjacent brain tissue or vasculature, for instance, if the meningioma is causing symptoms or growing rather rapidly and the neurosurgeon wants to remove it with surgery. But this might not be the best-case scenario and even prove to be too risky since the tumor is too close to a vital brain structure or blood vessel. In such cases, if surgery is performed, it is only done to take out as much of the tumor as possible. MRI imaging of the brain can help guide the surgery. The surgery for meningioma varies from relatively straightforward to highly complex, sometimes requiring multiple surgeons from different specialties. Surgical planning may include a neurological examination and a study of the MRI and CT scans, followed by an angiogram to determine how the tumor is affecting the surrounding vessels and to identify any vessels that might be supplying blood to the tumor. A surgeon can then perform:

• an Embolization: it is usually a pre-operative procedure done to stop the blood supply to the tumor. It is performed at the time of the angiogram to also reduce the amount of bleeding during surgery. This specific procedure is carried out by interventional neuroradiologists.
• a Craniotomy is when the neurosurgeon opens the skull to reach a meningioma on the brain’s surface, enabling full access to the tumor. Craniotomies are performed under general anesthesia. An incision is made in the scalp and a small part of the skull is removed to create an opening. A surgical microscope is then used to provide a high magnification of the tumor and its surrounding structures. After this, as much of the growth is removed as possible. The hole is finally covered with the removed portion of the skull and the skin is stitched together. Craniotomy may also be used for tumors found in some areas of the skull base, such as near the brainstem, where the brain meets the spinal cord.
• an Endoscopic Endonasal Surgery is done for a meningioma present in the base of the skull which can be reached through the nose. This procedure also requires the administration of general anesthesia but is minimally invasive. Otolaryngologists are doctors who specialize in ear, nose, and throat surgery, work as a team to perform this procedure.
• a Neuroendoscopic Surgery: in which the neurosurgeon inserts a tube through a small hole created in the skull. Via this endoscope and under computerized image guidance, called neuronavigation, surgeons can reach the tumors in the brain. This is useful for meningiomas found in the ventricular chambers. Administration of general anesthesia is also required for this procedure. And since only a small opening is created, neuroendoscopic surgery is minimally invasive.
• a Spinal Surgery: where an incision is made on the back near the upper or middle portion of the spine - the common location of these tumors in the spine. The procedure requires general anesthesia.

Radiation
Radiation can be established as a management plan for tumors that are inaccessible surgically, rather deep, or in the elderly. Depending on the areas of the brain or spinal cord that are involved, radiation therapy may help shrink any remaining tumor and help prevent it from spreading to the tissues around it. Even if the tumor is completely removed during surgery, some neurosurgeons may still recommend radiation therapy to help prevent recurrence in the future. Types of radiation therapy include:

1. Standard external beam radiotherapy
2. Stereotactic radiosurgery: Gamma Knife, Novalis, and Cyberknife

What does Recovery after Surgery look like?

The majority of meningiomas are benign and patients are typically considered surgically cured once tumor resection is complete. However, post-operatively special care is taken for pain control, even so much as mild movement can cause an increase in the level of pain. A dramatic increase in pain levels for no apparent reason must be reported but hoping that your hospital visit is completely pain-free is unreasonable.

Recovery also includes the prevention of complications which include damage to nearby normal brain tissue, bleeding, spinal fluid leakage, and infection. Prior to discharge, it is essential that any special requirements for returning home are addressed.

Once the patient is discharged, timed visits to the doctor will be scheduled to determine the absence of recurrence. Further imaging can also be performed for the same reason or to check brain health. The patient will additionally be required to consult a team of psychologists to deal with the emotional aspect of being a cancer survivor to help regain their footing in society.

Your healthcare provider is the best source of information for questions and concerns related to your medical problem. This article, however, is useful for acquiring surface knowledge regarding your diagnosis. Meningioma can be scary but doing your research and equipping yourself with the right information holds the potential promise of improved outcomes, especially when one is faced with a critical or life-threatening disease or condition. This access to information can make the difference between positive clinical outcomes and death.