By Eduardo Gonzales, MD
Is it true that even benign brain tumors can be fatal? Why? What are the symptoms of brain tumor? –[email protected]
Unlike malignant or cancerous tumors, which grow fast and spread or metastasize to other organs of the body, benign tumors grow slowly and do not metastasize. They also respond well to treatment and have excellent prognoses, which is why people who have breast or liver masses, for example, are greatly relieved when their tumors turn out to be benign. But for benign tumors in the brain, the outlook is not as rosy because of a couple of reasons. First, the brain is encased by the skull, which is made up of hard and rigid bone. Hence, a tumor or mass that grows inside the brain—albeit slowly, as in a benign tumor—will have no room to expand into and will instead compress and destroy brain tissue. Secondly, masses in the brain are usually difficult to access surgically. In addition, nerve tissue is very fragile and has minimal capacity to regenerate. Hence, any manipulation of the brain could result in permanent damage.
Causes and types of brain tumors
About half of brain tumors, referred to as secondary or metastatic tumors, represent the spread or metastases into the brain of a malignant or cancerous tumor from another organ of the body, e.g., breast cancer in women and lung cancer in men.
The other half of brain tumors, referred to as primary brain tumors, arise from structures within the brain. They are classified according to the type of cell from which they arise. Those that come from supporting cells of the brain are called gliomas, and those from the pituitary gland pituitary adenomas, while those from blood vessels are hemangiomas, etc.
Most primary brain tumors are benign, but, as already mentioned, they are also as dangerous as malignant ones.
We don’t know yet what causes primary brain tumors. Children who receive radiation to the head have a higher risk of developing a brain tumor as adults, as do people who have certain rare genetic conditions, such as neurofibromatosis. Age is also a risk factor. Primary brain tumors usually occur in patients over 45 years of age, with the peak incidence occurring in the seventh decade of life. Other possible risk factors for brain tumors that have been scientifically investigated include cellphones, head injuries, and exposure to chemicals and magnetic fields. But to date, studies have not shown consistent link between these factors and brain tumors.
Symptoms of brain tumors
The signs and symptoms of brain tumors vary according to the type of tumor, its location, and rate of growth. Some tumors have no symptoms until they are quite large and then cause a serious, rapid decline in health. Others have symptoms that appear early and develop slowly.
The most common symptom of brain tumors is headache, which recurs more frequently and severely with time. Other common symptoms are personality changes, impairment of intellectual functions, emotional liability, convulsions, nausea, vomiting, disturbances oractual loss of vision, dizziness, loss of balance, lack of coordination, and other neurological manifestations.
How are brain tumors diagnosed?
Two imaging techniques—CT scanning and MRI—singly or together can accurately define the location, shape, and size of brain tumors. CT scanning is a sophisticated version of the traditional x-ray examination, while MRI (magnetic resonance imaging)uses electromagnetic fields to create a three-dimensional image of the body’s internal structures.
To determine the type of tumor, a biopsy is often performed. This involves obtaining a tissue sample, either during the surgery to remove the tumor or with a needle inserted through a small hole drilled into the skull, and examining the sample under the microscope.
Treatment and outlooks of brain tumors
The treatment of a brain tumor depends on the type and location of the tumor. Surgical removal is the preferred treatment modality for most cases. But if the tumor is in a surgically inaccessible area, or if surgery is otherwise contraindicated, irradiation, chemotherapy, or just medical management to relieve the increased intracranial pressure might be the only viable treatment alternatives. Tumors that are deep in the brain, or those in areas that are difficult to reach may be treated with gamma knife therapy, which is a form of highly focused radiation therapy.
In primary brain tumors, total cure is a reasonable expectation if the mass can be totally removed by surgery. Most other forms of inoperable or only partially operable brain tumors also have long survival rates, but a few are fast growing and rapidly fatal.
For metastatic tumors, the outcome usually depends on the behavior of the primary tumor.
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