Metastatic brain tumor is a mass created by the growth of abnormal cells in the brain. This occurs when cancerous cells travel to the brain from another location in the body.
Alternative Names
Brain tumor - secondary; Tumor - brain - metastatic; Brain tumor - metastatic; Cancer - brain tumor (secondary)
Causes, incidence, and risk factors
Metastatic (secondary) brain tumor occurs when there is a tumor in an area of the body, most commonly the lungs or the breast, and cells from that tumor break off, travel in the bloodstream (metastasize), and lodge in the brain. The tumor cells then begin proliferating in the brain tissue. Tumors may be localized to a small area or invasive (spread to nearby areas). Tumors may directly destroy brain cells or indirectly damage cells from inflammation, compression from growth of the tumor, cerebral edema (brain swelling ), and increase in intracranial pressure (the pressure within the skull). Classification of metastatic brain tumors depends on the exact site of the tumor within the brain, type of tissue involved, original location of the tumor, and other factors. Metastatic brain tumors occur in about one-fourth of all cancers that metastasize (spread through the body). They are uncommon, but are more common than primary brain tumors . They occur in approximately 4 out of 100,000 people. Specific symptoms, treatment, and prognosis (probable outcome) vary according to the site and type of the tumor, original location of the tumor, and the age and general health of the person.
Signs and tests
An examination reveals focal (localized) or general neurologic changes that are specific to the location of the tumor . Signs of increased intracranial pressure are also common. Some tumors may not show symptoms until they are very large and then cause rapid neurologic decline. The original (primary) tumor may already be known, or it may be discovered after examination of the tumor tissues indicates that it is a metastatic type of tumor.
A head CT scan or MRI of the head confirms the diagnosis of brain tumor and localizes the tumor.
Cerebral angiography may occasionally be performed. If performed, it may show a space-occupying mass, which may or may not be highly vascular (filled with blood vessels). A chest X-ray , mammogram , and other tests are performed to look for the original site of the tumor.
An EEG may reveal focal (localized) abnormalities.
An examination of tissue (removed from the tumor during surgery or CT scan-guided biopsy ) is used to confirm the exact type of tumor. If the primary tumor can be located outside of the brain, the primary tumor is usually biopsied rather than the brain tumor.
Treatment
Treatment varies with the size and type of the tumor , primary site of the tumor, and the general health of the person. The goals of treatment may be relief of symptoms, improved functioning, or comfort. Surgery is indicated for metastatic brain tumors when there is a single lesion. Some may be completely excised (removed). Tumors that are deep or that infiltrate brain tissue may be debulked (removal of much of the mass of the tumor to reduce its size). Surgery may reduce intracranial pressure and relieve symptoms in cases when the tumor cannot be removed. Radiation therapy may be advised for tumors that are sensitive to radiation. Medications may include:
Corticosteroids such as dexamethasone to reduce swelling of the brain
Osmotic diuretics such as urea or mannitol to reduce brain swelling Anticonvulsants such as phenytoin to reduce seizures
Analgesics to control pain Antacids or antihistamines to control stress ulcers When multiple metastases (widespread cancer ) is discovered, treatment may focus primarily on relief of pain and other symptoms. Comfort measures, safety measures, physical therapy, occupational therapy, and other interventions may improve the quality of life. Counseling, support groups, and similar measures may be needed to cope with the disorder. See cancer - support group in the special topics section. Legal advice may be helpful in forming advanced directives, such as power of attorney , in cases where continued physical or intellectual decline is likely.
Expectations (prognosis)
In general, The probable outcome is fairly poor. Many people with metastatic brain tumors have widespread tumor metastasis . Death often occurs within 2 years.
Calling your health care provider
Call for an appointment with your health care provider if new, persistent headaches occur. Go to the emergency room if there is a new onset of seizures , or sudden development of stupor , vision changes, or speech impairment .
Prevention
Early detection and treatment of primary tumors may prevent some metastatic brain tumors.