What is a Brain Tumor?
A brain tumor is an abnormal growth of tissue in the brain. The tumor can either originate in the brain itself, or come from another part of the body and travel to the brain (metastasize). Brain tumors may be classified as either benign (non-cancerous) or malignant (cancerous), depending on their behavior.
A benign tumor does not contain cancer cells and usually, once removed, does not recur. Most benign brain tumors have clear borders, meaning they do not invade surrounding tissue. These tumors can, however, cause symptoms similar to cancerous tumors because of their size and location in the brain.
Malignant brain tumors contain cancer cells. Malignant brain tumors are usually fast growing and invade surrounding tissue. Malignant brain tumors very rarely spread to other areas of the body, but may recur after treatment. Sometimes, brain tumors that are not cancer are called malignant because of their size and location, and the damage they can do to vital functions of the brain.
Metastatic brain tumors are tumors that begin to grow in another part of the body, then spread to the brain through the bloodstream. Common types of cancer that can travel to the brain include lung cancer, breast cancer, melanoma (a type of skin cancer), and colon cancer. All of these cancers are considered malignant once they have spread to the brain.
Types of Brain Tumors
There are many different types of brain tumors. They are usually categorized by the type of cell where the tumor begins, or they are categorized by the area of the brain where they occur.
Astrocytomas are glial cell tumors that are derived from connective tissue cells called astrocytes. These cells can be found anywhere in the brain or spinal cord. Astrocytomas are the most common type of childhood brain tumor, and the most common type of primary brain tumor in adults. Astrocytomas are generally subdivided into high-grade, medium-grade or low-grade tumors. High-grade astrocytomas are the most malignant of all brain tumors.
Astrocytomas are further classified for presenting signs, symptoms, treatment, and prognosis, based on the location of the tumor. The most common location of these tumors in children is in the cerebellum, where they are called cerebellar astrocytomas. These persons usually have symptoms of increased intracranial pressure, headache, and vomiting. There can also be problems with walking and coordination, as well as double vision. In adults, astrocytomas are more common in the cerebral hemispheres (cerebrum), where they commonly cause increased intracranial pressure (ICP), seizures, or changes in behavior.
Brain Stem Gliomas
Brain stem gliomas are tumors found in the brain stem. Most brain stem tumors cannot be surgically removed because of the remote location and delicate and complex function this area controls. Brain stem gliomas occur almost exclusively in children; the group most often affected is the school-age child. The child usually does not have increased intracranial pressure (ICP), but may have problems with double vision, movement of the face or one side of the body, or difficulty with walking and coordination.
The most common type of primary brain tumor is a glioma. Gliomas begin from glial cells, which are the supportive tissue of the brain. There are several types of gliomas, categorized by where they are found, and the type of cells that originated the tumor.
Glioblastoma multiforme (GBM) is the most common glioma (a type of brain cancer). It represents nearly one fourth of all primary brain tumors. This cancer starts in the glial cells, which are cells that help nerve cells work.
Ependymomas are also glial cell tumors. They usually develop in the lining of the ventricles or in the spinal cord. The most common place they are found in children is near the cerebellum. The tumor often blocks the flow of the CSF (cerebral spinal fluid, which bathes the brain and spinal cord), causing increased intracranial pressure. This type of tumor mostly occurs in children younger than 10 years of age. Ependymomas can be slow growing, compared to other brain tumors, but may recur after treatment is completed. Recurrence of ependymomas results in a more invasive tumor with more resistance to treatment. Two percent of brain tumors are ependymomas.
Hemangioblastomas are tumors usually located in the cerebellum and spinal cord. They can cause significant problems, for example angiomas in the brain or spinal cord may press on nerve or brain tissue. The tumors can occur as the result of von Hippel-Lindau disease.
Optic nerve gliomas
Optic nerve gliomas are found in or around the nerves that send messages from the eyes to the brain. They are frequently found in persons who have neurofibromatosis, a condition a child is born with that makes him/her more likely to develop tumors in the brain. Persons usually experience loss of vision, as well as hormone problems, since these tumors are usually located at the base of the brain where hormonal control is located. These are typically difficult to treat because of the surrounding sensitive brain structures.
This type of tumor also arises from the supporting cells of the brain. They are found commonly in the cerebral hemispheres (cerebrum).are a very common symptom of these tumors, as well as headache, weakness, or changes in behavior or sleepiness. This tumor is more common in persons in their 40s and 50s. These tumors have a better prognosis than most other gliomas, but they can become more malignant with time.
Uveal melanoma is cancer (melanoma) of the eye. Common surgical treatment for uveal melanomas is enucleation (removal of the eye), and other therapeutic options include radium plaque therapy and proton beam therapy. Gamma Knife surgery is becoming a more frequently used procedure for this unusual condition.
The majority of brain tumors have abnormalities of genes involved in cell cycle control, causing uncontrolled cell growth. These abnormalities are caused by alterations directly in the genes, or by chromosome rearrangements which change the function of a gene.
Genetics: Patients with certain genetic conditions (i.e., neurofibromatosis, von Hippel-Lindau disease, Li-Fraumeni syndrome, and retinoblastoma) also have an increased risk to develop tumors of the central nervous system. There have also been some reports of people in the same family developing brain tumors who do not have any of these genetic syndromes.
Chemical Exposure: Research has been investigating parents of children with brain tumors and their past exposure to certain chemicals. Some chemicals may change the structure of a gene that protects the body from diseases and cancer. Workers in oil refining, rubber manufacturing, and chemists have a higher incidence of certain types of tumors. Which, if any, chemical toxin is related to this increase in tumors is unknown at this time.
Radiation: Patients who have received radiation therapy to the head as part of prior treatment for other malignancies are also at an increased risk for new brain tumors.
The following are the most common symptoms of a brain tumor. However, each person may experience symptoms differently. Symptoms vary depending on the size and location of tumor. Many symptoms are related to an increase in pressure in or around the brain. There is no spare space in the skull for anything except the delicate tissues of the brain and its fluid. Any tumor, extra tissue, or fluid can cause pressure on the brain and result in increased intracranial pressure (ICP), which may result from one or more of the ventricles that drain cerebral spinal fluid (CSF, the fluid that surrounds the brain and spinal cord) becoming blocked and causing the fluid to be trapped in the brain. This increased ICP may cause the following:
- vomiting (usually in the morning)
- personality changes
- decreased cardiac and respiratory function and, eventually, coma if not treated
Symptoms of brain tumors in the cerebrum (front of brain) may include:
- increased intracranial pressure (ICP)
- visual changes
- slurred speech
- paralysis or weakness on half of the body or face
- drowsiness and/or confusion
- personality changes/impaired judgment
- short-term memory loss
- gait disturbances
- communication problems
Symptoms of brain tumors in the brainstem (middle of brain) may include:
- increased intracranial pressure (ICP)
- endocrine problems (diabetes and/or hormone regulation)
- visual changes or double vision
- paralysis of nerves/muscles of the face, or half of the body
- respiratory changes
- clumsy, uncoordinated walk
- hearing loss
- personality changes
Symptoms of brain tumors in the cerebellum (back of brain) may include:
- increased intracranial pressure (ICP)
- vomiting (usually occurs in the morning without nausea)
- uncoordinated muscle movements
- problems walking (ataxia)
The symptoms of a brain tumor may resemble other conditions or medical problems. Always consult your physician for a diagnosis.
In addition to a complete medical history and physical examination, diagnostic procedures for brain tumors may include the following:
- Neurological examination
Your physician tests reflexes, muscle strength, eye and mouth movement, coordination, and alertness.
- Computed tomography scan (also called a CT or CAT scan)
a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general x-rays.
- Magnetic resonance imaging (MRI)
a diagnostic procedure that uses a combination of large magnets, radio frequencies, and a computer to produce detailed images of organs and structures within the body.
a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.
- Bone scan
pictures or X-rays taken of the bone after a dye has been injected that is absorbed by bone tissue. These are used to detect tumors and bone abnormalities.
- Arteriogram (also called an angiogram)
an x-ray of the arteries and veins to detect blockage or narrowing of the vessels.
a procedure that uses dye injected into the spinal canal to make the structure clearly visible on x-rays.
- Spinal tap (also called a lumbar puncture)
a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems. CSF is the fluid that bathes the brain and spinal cord.
- Positron emission tomography (PET)
a type of nuclear medicine procedure. This means that a tiny amount of a radioactive substance, called a radionuclide (radiopharmaceutical or radioactive tracer), is used during the procedure to assist in the examination of the tissue under study. Specifically, PET studies evaluate the metabolism of a particular organ or tissue, so that information about the physiology (functionality) and anatomy (structure) of the organ or tissue is evaluated, as well as its biochemical properties. Thus, PET may detect biochemical changes in an organ or tissue that can identify the onset of a disease process before anatomical changes related to the disease can be seen with other imaging processes such as computed tomography (CT) or magnetic resonance imaging (MRI). UVa has a PET/CT scanner, which combines the advantages of PET and CT scanning to get a more precise look at any potential tumors and their activity.
- Magnetic resonance spectroscopy (MRS)
a procedure that produces images depicting function rather than shape. The equipment requires a special, highly complex facility.
- Surgical biopsy
the process of removing at least some of the tumor in order to examine it in a lab. In a craniotomy, the surgeon will also remove as much of the tumor as is safely possible. For tumors in a part of the brain that is difficult to reach, a surgeon may perform a stereotactic biopsy, during which a small sample of the tumor is extracted using a needle.
Diagnosis of a brain tumor depends mostly on the types of cells involved and the tumor location.
UVA is home to some of the most advanced technologies for the treatment of brain and spinal cord tumors, including:
- Clinical trials
UVA has an active clinical trials program, with many clinical trials developed by UVA researchers and physicians. We participate in many National Cancer Institute-supported clinical trials. Additionally, because we see many patients with brain tumors, we have access to the newest and most promising pharmaceutical company trials as well. Our partners in clinical trials include Harvard, Mayo Clinic and Memorial Sloan-Kettering Cancer Center.
- Expertise in chemotherapy for gliomas, brain lymphoma and meningiomas
Since brain tumors account for only 1-2% of all cancer, most oncologists have little familiarity with their management. UVA's neuro-oncologists, Drs. Schiff and Purow, exclusively see patients with neuro-oncologic disorders and are up to date on the full spectrum of standard and experimental strategies. This expertise allows us to offer promising therapies that are unavailable through clinical trials and that are unfamiliar to most general oncologists. Such approaches include bevacizumab (Avastin) for high-grade gliomas and the use of chemotherapy as the initial treatment of low-grade gliomas.
UVA is an international training site for the Gamma Knife, a powerful instrument designed to direct exquisitely precise radiation to tumors in the brain without performing brain surgery. UVA physicians pioneered the use of this technology.
- Skull Base Center
Our Skull Base Center brings together specialists in neurosurgery, head and neck surgery, sinus and skull base surgery, ear disorders (otology/neurotology), neuroradiology, pituitary disorders (endocrinology) and radiation oncology. These specialists work as a team to treat difficult-to-reach skull base tumors.
- Gene therapy is a special gene is added to a virus that is injected into the brain tumor. An antivirus drug is then given which kills the cancer cells that have been infected with the altered virus.
- Molecular cytogenetics a specialized technique helps to predict prognosis and to determine which brain tumors will respond best to chemotherapy.
- PET/CT an advanced imaging system is capable of finding some tumors before they are visible on more traditional systems. It is also useful in differentiating tumor from radiation damage. UVA had the first PET/CT scanner in Virginia.
- Pituitary surgery
UVA has renowned experts in the field of pituitary surgery, performing more of these procedures than any other center in the world.
- Real-time surgery analysis
Our neurosurgeons can do an MRI mid-surgery to make sure they removed the entire brain tumor and potentially prevent a second surgery.
Specific treatment for brain tumors will be determined by your physician based on:
- your age, overall health, and medical history
- type, location, and size of the tumor
- extent of the condition
- your tolerance for specific medications, procedures, or therapies
- expectations for the course of the condition
- your opinion or preference
Treatment may include (alone or in combination):
- Surgery is usually the first step in the treatment of brain tumors. The goal is to remove as much of the tumor as possible while maintaining neurological function. A biopsy is also done to examine the types of cells the tumor is made of for a diagnosis. This is frequently done if the tumor is in an area with sensitive structures around it that may be injured during removal.
- Radiation therapy
- Steroids are used to treat and prevent swelling, especially in the brain.
- Anti-seizure medication treats and prevents seizures associated with intracranial pressure.
- Placement of a ventriculoperitoneal shunt (also called a VP shunt), which is a tube that is placed into the fluid filled spaces of the brain called ventricles. The other end of the tube is placed into the abdomen to help drain excess fluid that can build up in the brain and cause an increase in pressure in the brain.
- Bone marrow transplantation
- Supportive care minimizes the side effects of the tumor or treatment.
- Rehabilitation may be necessary to regain lost motor skills and muscle strength; speech, physical, and occupational therapists may be involved in the healthcare team.
- Antibiotics treat and prevent infections.
- Continuous follow-up care helps manage disease, detect recurrence of the tumor, and to manage late effects of treatment.