Meningioma

The brain is wrapped in layers of membranes called meninges. A meningioma is atumour that grows out of the meninges, particularly the one known as the arachnoid layer (so called because it looks like a web). A meningioma is usually benign, although a small percentage are malignant (cancerous).

The tumor typically grows slowly and doesn’t spread to any other part of the body. Close to one in five brain tumors are meningiomas. Women and older people are more likely to develop this type of tumor, for reasons unknown.

Symptoms depend on the size and location of the meningioma, but may include headaches and seizures.

The primary form of treatment is surgery to remove the tumor completely#

In rare cases, this isn’t always possible because the meningioma is inaccessible, or parts may have invaded important blood vessels or nerves.

The symptoms of meningioma depend on the location, type and size but may include:

• Impairment of brain functioning
• depending on the location of the tumor

Meningiomas are classified according to their appearance#

For example, they may be cellular or fibrous or contain plenty of blood vessels.

Another classification method is by location#

Associated symptoms for a selection of meningioma locations may include:

• Between the brain lobes (parasagittal) - paralyzis of usually one leg. Underneath the brain
• behind the nose (olfactory groove) - loss of the sense of smell (anosmia). Underneath the brain
• behind the eye (sphenoid wing) - seizures
• multiple cranial nerve palsies

Rear of the brain (occipital lobe) - loss of half of the field of vision in one eye (contralateral hemianopsia). Spinal cord - pain in the spine, weakness and decreased ability to ‘sense’ the body’s location. The symptoms of a meningioma can be triggered by various means including: Compression - the tumor may be large enough to squash the underlying brain tissue.

Headaches are a common symptom#

Irritation - the nerves of the brain may be irritated and disrupted by the tumor’s presence, particularly if the tumor is located over the cortex (uppermost layer of the brain).

Seizures are a common symptom of cortex irritation#

Invasion - the tumor may invade brain tissue. Symptoms depend on which parts of the brain are affected. Injuries to blood vessels - the tumor may disrupt blood flow to various parts of the brain by injuring or blocking the blood vessels.

The arachnoid layer is one of the membranes surrounding the brain. A meningioma grows from cells in the arachnoid layer called arachnoid cap cells.

These cells help to regulate the amount of fluid within the brain#

However, the cause of meningiomas is unknown#

Risk factors are thought to include: Female hormones#

Meningiomas are diagnosed using a number of tests including: Biopsy. About eight out of 10 meningiomas can be cured. Treatment depends on the location, type and size of the tumor but may include:

• Close monitoring - your doctors may prefer to simply watch
• monitor a small tumor

Steroid medications - to help reduce the inflammation and swelling around the tumor.

A low-salt diet is also recommended#

Anti-epileptic drugs - to reduce the risk of brain seizures. Surgery - the aim is to remove the tumor, or at least all parts that are safe to remove.

Surgery to remove a meningioma is called a craniotomy. Ideally, the entire tumor is removed during the operation.

If the tumor is located on the surface of the brain, complete removal (resection) is highly possible.

However, meningiomas in hard-to-reach locations (such as underneath the brain) are difficult to remove because they are surrounded by so many vital structures. Sometimes, the tumor might be in an accessible location, but has invaded blood vessels or wrapped around nerve fibers.

To reduce the risk of complications such as injury to the brain, the surgeons may have to leave some parts of the tumor behind.

Normal activities can be resumed in around one to three months after surgery, depending on individual circumstances.

After surgery, you will be slowly weaned off steroid medication, although it is sometimes necessary to continue taking anti-epileptic drugs for life. If only parts of the meningioma were removed, regular scans help to monitor the remaining tumor and keep track of its growth rate.

Subsequent operations may be needed#

On the other hand, some meningiomas grow so slowly that they are virtually the same size some 10 years after the craniotomy. Even if the meningioma was completely removed during surgery, you will still need regular check-ups to ensure it hasn’t returned, including scans for around five years. Occupational therapy, physiotherapy, speech therapy or other forms of rehabilitative health care may be necessary.

In some cases, the meningioma grows back after surgery. This is more likely to happen if only parts of the tumor were removed. Options may include: Radiosurgery (surgery using narrow beams of radiation).

Symptoms of meningioma Seizures (fits) Headaches Symptoms depend on location How meningiomas cause symptoms The cause of meningioma is unknown Advancing age Prior radiation therapy Chromosomal abnormalities Diagnosis of meningioma Physical examination Medical history Skull x-ray Computed tomography (CT) scan Magnetic resonance imaging (MRI) scan Treatment for meningioma Craniotomy is the preferred treatment Ongoing monitoring is important Treatment for a return meningioma Repeat surgery Radiotherapy Chemotherapy

Where to get help#

Key Points#

• Symptoms depend on the size and location of the meningioma, but may include headaches and seizures
• primary form of treatment is surgery to remove the tumor completely
• Headaches are a common symptom
• Seizures are a common symptom of cortex irritation
• Symptoms depend on which parts of the brain are affected