Meningioma is the most common type of brain tumour in Singapore.

Meningiomas grow on the meninges, which is the multilayered protective tissue covering the brain and spinal cord.

Most meningiomas are slow growing as well as non-cancerous (benign), which means that they don’t spread to other parts of the body. However, if a meningioma becomes large, it can put pressure on the brain or spinal cord, irritate cranial nerves and injure blood vessels in the brain, leading to debilitating symptoms.

Occasionally, a meningioma can grow outward and cause the skull to thicken.

“NNI sees about 50-60 cases of meningioma per year. Only about 2 to 3 per cent of these are cancerous,” says Professor Ng Wai Hoe, Senior Consultant from the Department of Neurosurgery at National Neuroscience Institute (NNI), a member of the SingHealth group.

The typical patient is in the 40 to 60 year-old group. There is a slight female predilection (3:2 ratio).

Causes of meningioma

In the majority of cases, the exact cause of meningioma remains unknown.

But people with neurofibromatosis type 2, a rare and inherited nervous system disorder, are more susceptible to meningioma.

In some cases, an abnormality in the chromosome 22 has been found, but the cause of this abnormality is uncertain.

Meningioma symptoms

Most benign meningioma tumours do not show any symptoms until they become large and start increasing intracranial pressure. Symptoms vary from patient to patient, depending on the meningioma’s location in the brain. These can include:

  • Persistent headaches and seizures (due to pressure and irritation on the surface of the brain

  • Double and blurred vision (if the meningioma compresses the optic nerve or is large enough to cause generalized increase in pressure)

  • Numbness and weakness in the arms and legs (if the meningioma is near the brain’s motor and sensory areas)

  • Loss of smell, taste, hearing and memory (if the meningioma grows in the cranial cavity between the brow and nose)

How is meningioma diagnosed

Doctors can use a variety of tests to diagnose meningioma. These include a computed tomography (CT) scan and magnetic resonance imaging (MRI) scan. The scans will help determine the size, location and grade of the brain tumour.

3 Types of meningioma treatment

1. Observation

Small, slow-growing benign meningioma tumours without any significant symptoms may not require immediate treatment, especially in the elderly. Doctors will often recommend a period of watchful waiting and periodic brain scans to monitor any signs of tumour growth.

2. Surgery

The majority of meningiomas can be treated with surgery.
"Meningioma tumours can generally be removed if they are located near the brain’s surface and have not invaded any critical structures such as the optic nerve and brain stem," says Professor Ng.

Steroids are often given to reduce brain swelling before and after the operation. Some patients may develop seizures after surgery, so anti-convulsants may be prescribed before and after surgery to prevent seizures.

3. Radiation therapy or radiosurgery

If the meningioma is malignant, is not suitable for surgery or can only be partially removed by surgery, radiation therapy will be considered.

Radiation therapy is used to destroy the meningioma cells, shrink the tumour or prevent it from growing bigger.

In small meningiomas, stereotactic radiosurgery using the Novalis shaped-beam surgery system is the preferred method. It allows delivery of a high dose of radiation directly to the brain tumour with no or minimal damage to surrounding brain structures.

Ref: R14

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Brain Tumour: Causes, Types, Diagnosis and Treatment

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