A primary brain tumor is a mass of abnormal cells that starts in the brain. Benign tumors can often be removed, and they seldom grow back. They have an obvious border or edge, and cells from benign tumors rarely invade tissues around them. However, they can press on sensitive areas of the brain and cause neurological symptoms. Benign brain tumors may also become malignant.
Malignant brain tumors, also called brain cancer, are life threatening. They are likely to grow rapidly and crowd or invade nearby healthy brain tissue. Cancer cells may break away from malignant brain tumors and spread to other parts of the brain or to the spinal cord.
The cause of primary brain tumors is unknown. Risks factors that could play a role include:
- Radiation therapy to the brain, used to treat brain cancers, increases the risk for brain tumors up to 20 or 30 years afterwards.
- Some inherited conditions increase the risk of brain tumors, including neurofibromatosis, Von Hippel-Lindau syndrome, Li-Fraumeni syndrome and Turcot syndrome.
Exposure to radiation at work or to power lines, as well as head injuries, smoking and hormone replacement therapy have NOT been proven to be risk factors. Recent studies have found that cell phones, cordless phones and wireless devices do not increase the risk.
Brain tumors are classified depending on the location of the tumor, the type of tissue involved and whether they are benign or malignant.
Gliomas come from glial cells such as astrocytes, oligodendrocytes and ependymal cells. Gliomas are divided into three types:
Astrocytic tumors include astrocytomas (which may be benign), anaplastic astrocytomas and glioblastomas.
Oligodendroglial tumors arise from cells that make the fatty substance that covers and protects nerves. Some primary brain tumors are made up of both astrocytic and oligodendrocytic tumors. These are called mixed gliomas.
Glioblastomas are the most aggressive type of primary brain tumor. Glioblastoma multiforme (GBM) is a fast-growing glioma that develops from astrocytes – star-shaped glial cells that support nerve cells. GBM is the most invasive of all glial tumors, growing rapidly and commonly spreading to nearby brain tissue.
Meningiomas and schwannomas occur most often between ages 40 and 70. They are usually benign but may cause serious complications and death from their size or location. Some are malignant and aggressive. Meningiomas are much more common in women. Schwannomas affect both genders equally.
Other primary brain tumors in adults are rare, including:
- Pituitary tumors
- Primary CNS lymphoma
- Primary lymphoma of the brain
- Pineal gland tumors
- Primary germ cell tumors of the brain
Symptoms depend on the tumor’s size, location, how far it has spread and whether there is swelling. The most common symptoms are:
- Changes in mental function
- Seizures, especially in older adults
- Weakness in one part of the body
- Change in alertness, including sleepiness, unconsciousness and coma
- Changes in hearing
- Changes in taste or smell
- Changes that affect touch and the ability to feel pain, pressure, different temperatures or other stimuli
- Confusion or memory loss
- Difficulty swallowing
- Difficulty writing or reading
- Dizziness or abnormal sensation of movement (vertigo)
- Eye problems such as eyelid drooping or pupils of different sizes
- Uncontrollable movements
- Hand tremor
- Lack of control over the bladder or bowels
- Loss of balance or coordination
- Muscle weakness in the face, arm or leg (usually on one side)
- Numbness and tingling on one side of the body
- Personality, mood, behavior or emotional changes
- Problems with eyesight, including decreased vision, double vision or total loss of vision
- Trouble speaking or understanding others who are speaking
- Trouble walking
Most brain tumors increase pressure on the skull and press on brain tissue because of their size and weight. The following tests may confirm the presence of a brain tumor and find its location:
- CT scan of the head
- MRI of the head
- Electroencephalogram (EEG)
- Examination of tissue removed from the tumor during surgery or a CT-guided biopsy to confirm the type of tumor
- Examination of the cerebrospinal fluid (CSF) for malignant cells
Doctors group tumors by type and grade. Grade I tissue is benign and grows slowly. Grade II tissue is malignant. Grade III tumors have abnormal cells that are actively growing. In Grade IV tumors the malignant tissue has cells that look abnormal tend to grow quickly.
Early treatment often improves the chance of a good outcome. Your treatment plan may involve surgery, radiation therapy and chemotherapy. Brain tumors are best treated by a multidisciplinary team that includes a neuro-oncologist, neurosurgeon, oncologist, radiation oncologist and other healthcare providers, such as neurologists and social workers.
The type of treatment depends primarily on the following:
- Type and grade of brain tumor
- Its location in the brain
- Its size
- Your age and general health
For some types of brain cancer, the doctor also needs to know whether cancer cells were found in the cerebrospinal fluid.
Your doctor will explain your treatment choices, the expected results and the possible side effects. Because cancer therapy often damages healthy cells and tissues, side effects are common. Before treatment starts, ask your healthcare team about possible side effects and how treatment may change your normal activities. We work with our patients to develop a treatment plan that meets their medical and personal needs.
Surgery is usually needed for most primary brain tumors. Some tumors may be completely removed. Those that are deep inside the brain or that enter healthy brain tissue may be debulked – a procedure to reduce the tumor’s size – instead of removed. When the tumor cannot be removed, surgery may still help reduce pressure and relieve symptoms.
We also provide the option of stereotactic radiosurgery using the Novalis Tx™, a powerful radiosurgery and radiotherapy system that penetrates deeper and faster into the body to treat tumors considered inoperable.
In addition to surgery, radiation therapy is used for certain types of tumors, and chemotherapy may be used with surgery or radiation treatment.
Other medications used to treat primary brain tumors in children may include:
- Corticosteroids, such as dexamethasone, to reduce brain swelling
- Medicines such as urea or mannitol to reduce brain swelling and pressure
- Anticonvulsants, such as evetiracetam, to reduce seizures
- Pain medications
Comfort measures, safety measures, physical therapy and occupational therapy may be needed to improve quality of life. Counseling and support groups are available to help our patients and their families cope with brain tumor.
Source: National Institutes of Health and National Cancer Institute