Nicholas R. Metrus, MD, is a board-certified neurologist and neuro-oncologist. He currently serves at the Glasser Brain Tumor Center in Summit, New Jersey.
A brain tumor is a mass of abnormal cells that grow in the brain. Brain tumors can be benign (non-cancerous) or malignant (cancerous). They can originate in the brain itself or be the result of cancer that has spread from another part of the body. Those that are cancerous frequently grow rapidly, while those that are not tend to grow more slowly.
While benign tumors are generally less worrisome when they occur in other parts of the body, in the brain they often grow large enough to disrupt normal functioning. If they do, surgery is required.
Seizures and severe headaches are usually the first sign a brain tumor might be present. Other symptoms can include cognitive changes, loss of consciousness, and dizziness. Brain tumors can also present with weakness or numbness in just one part of the body. Headaches that are tumor-related are generally unusually severe or will be combined with other symptoms, such as vomiting or fever.
Symptoms of a brain tumor may be mild and subtle or severe and life-threatening, and are usually related to impairment in the area of the brain where the tumor is located. Only a full medical evaluation can determine whether a brain tumor is causing your neurological or other symptoms, which may also be caused by many other conditions.
Tumors can grow rapidly or be slow-growing. Tumors are classified according to grades (numbered I to IV) that rank how quickly they grow and spread to other tissues. Tumors called gliomas, which start in glial brain cells, make up more than three-quarters of malignant, quickly growing brain tumors. However, only about a third of brain tumors are gliomas.
The term benign refers to a tumor that is noncancerous, meaning it won't invade nearby tissues or spread to other areas of the body (metastasize). A benign tumor is less worrisome than a malignant tumor unless it is pressing on nearby tissues, nerves, or blood vessels. Benign tumors may need to be removed by surgery, such as when they occur in the brain or interfere with other normal functions.
The term malignant is used to refer to a tumor that is made up of cancer cells. Some cancer cells can move into the bloodstream or lymph nodes, then spread to other tissues, in a process called metastasis. Malignant cancer can occur anywhere in the body, including the brain, breasts, intestines, lungs, reproductive organs, blood, and skin.
Metastatic brain tumors are made up of cancer cells that originate from somewhere else in the body, such as the lungs, breast, colon, kidneys, or immune cells, and then travel to the brain, causing damage. All metastatic brain tumors are malignant.
A neurological examination—sometimes described as a neuro exam—may involve evaluating cognitive functioning, motor strength and control, sensory function, gait (walking), cranial nerve testing, or balance. It is used to diagnose neurological conditions such as a brain tumor, Parkinson’s disease, multiple sclerosis (MS), and spinal muscular atrophy.
A primary brain tumor can originate from a number of different cells in the brain, such as glial cells (glioma), astrocytes (astrocytoma), meninges (meningioma), or the pituitary gland (pituitary tumor). Primary brain tumors can be benign or malignant.
In a biopsy, a needle is used to obtain tissue that is checked in a lab for signs of cancer or other diseases. A stereotactic needle biopsy uses 3D and computer technology, such as CT and MRI scans, to guide the location of the needle that obtains a tissue sample.
American Association of Neurological Surgeons. Brain tumors.
American Cancer Society. Types of brain and spinal cord tumors in adults.