A primary brain tumor is a group (mass) of abnormal cells that start in the brain. This article focuses on primary brain tumors in adults.
Causes, incidence, and risk factors
Primary brain tumors include any tumor that starts in the brain. Primary brain tumors can start from brain cells, the membranes around the brain (meninges), nerves, or glands.
Tumors can directly destroy brain cells. They can also damage cells by producing inflammation, placing pressure on other parts of the brain, and increasing pressure within the skull.
The cause of primary brain tumors is unknown. There are many possible risk factors that could play a role.
- Radiation therapy to the brain, used to treat brain cancers, increases the risk for brain tumors up to 20 or 30 years afterwards.
- 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.
- The risk of using cell phones is hotly debated. However, most recent studies have found that cell phones, cordless phones, and wireless devices are safe and do not increase the risk.
- Some inherited conditions increase the risk of brain tumors, including neurofibromatosis, Von Hippel-Lindau syndrome, Li-Fraumeni syndrome, and Turcot syndrome.
- Lymphomas that begin in the brain in people with a weakened immune system are sometimes linked to the Epstein-Barr virus.
SPECIFIC TUMOR TYPES
Brain tumors are classified depending on:
- The location of the tumor
- The type of tissue involved
- Whether they are noncancerous (benign) or cancerous (malignant)
- Other factors
Sometimes, tumors that start out less aggressive can become more aggrssive.
Tumors may occur at any age, but many types of tumors are most common in a certain age group. In adults, gliomas and meningiomas are most common.
Gliomas come from glial cells such as astrocytes, oligodendrocytes, and ependymal cells. The gliomas are divided into three types:
- Astrocytic tumors include astrocytomas (can be noncancerous), anaplastic astrocytomas, and glioblastomas.
- Oligodendroglial tumors. 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.
Meningiomas and schwannomas are two other types of brain tumor. These tumors:
- Occur most often between ages 40 and 70
- Are usually noncancerous, but still may cause serious complications and death from their size or location. Some are cancerous and aggressive.
Meningiomas are much more common in women. Schwannomas affect both genders equally.
Other primary brain tumors in adults are rare. These include:
- Pituitary tumors
- Primary CNS lymphoma
- Primary lymphoma of the brain
- Pineal gland tumors
- Primary germ cell tumors of the brain
Some tumors may not cause symptoms until they are very large. Then they can quickly damage a person’s health. Other tumors have symptoms that develop slowly.
The 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 the person’s mental function
- Seizures (especially in older adults)
- Weakness in one part of the body
Headaches caused by brain tumors may:
- Be worse when the person wakes up in the morning, and clear up in a few hours
- Occur during sleep
- Occur with vomiting, confusion, double vision, weakness, or numbness
- Get worse with coughing or exercise, or with a change in body position
Other symptoms may include:
- 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
- Hand tremor
- Lack of control over the bladder or bowels
- Loss of balance
- Loss of coordination
- Muscle weakness in the face, arm, or leg (usually on just one side)
- Numbness or 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
Other symptoms that may occur with a pituitary tumor:
- Abnormal nipple discharge
- Absent menstruation (periods)
- Breast development in men
- Enlarged hands, feet
- Excessive body hair
- Facial changes
- Low blood pressure
- Sensitivity to heat or cold
Signs and tests
Most brain tumors increase pressure in 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:
Treatment can involve surgery, radiation therapy, and chemotherapy. Brain tumors are best treated by a team that includes:
- Radiation oncologist
- Other health care providers, such as neurologists and social workers
Early treatment often improves the chance of a good outcome. How you are treated depends on the size and type of tumor and your general health. The goals of treatment may be to cure the tumor, relieve symptoms, and improve brain function or comfort.
Surgery is often needed for most primary brain tumors. Some tumors may be completely removed. Those that are deep inside the brain or that enter brain tissue may be debulked instead of removed. Debulking is a procedure to reduce the tumor’s size.
Tumors can be hard to remove completely by surgery alone, because the tumor invades surrounding brain tissue much like roots from a plant spread through soil. When the tumor cannot be removed, surgery may still help reduce pressure and relieve symptoms.
Radiation therapy is used for certain tumors.
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 (Keppra), to reduce seizures
- Pain medications
- Antacids or histamine blockers to control stress ulcers
Comfort measures, safety measures, physical therapy, and occupational therapy may be needed to improve quality of life. Counseling, support groups, and similar measures can help people cope with the disorder.
You may consider enrolling in a clinical trial after talking with your treatment team.
Legal advice may be helpful for creating advanced directives such as a power of attorney.
Calling your health care provider
Call your health care provider if you develop any new, persistent headaches or other symptoms of a brain tumor.
Call your provider or go to the emergency room if you start having seizures, or suddenly develop stupor (reduced alertness), vision changes, or speech changes.
- Buckner JC, Brown PD, O’Neill BP, Meyer FB, Wetmore CJ, Uhm JH. Central nervous system tumors. Mayo Clin Proc. 2007;82(10):1271-1286.
- Stupp R, Roila F; ESMO Guidelines Working Group. Malignant glioma: ESMO clinical recommendations for diagnosis, treatment, and follow-up. Ann Oncol. 2009;20 Suppl 4:126-128.
- National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Central nervous system cancers. V.2.2009.
- Wen PY, Kesari S. Malignant gliomas in adults. N Engl J Med. 2008 Jul 31;359(5):492-507.
- Review Date: 12/1/2011.Reviewed by: Luc Jasmin, MD, PhD, Department of Neurosurgery at Cedars-Sinai Medical Center, Los Angeles, and Department of Anatomy at UCSF, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
Copyright © 2012, A.D.A.M., Inc.