Cancer in the brain tissue frequently is the result of metastasis from other body organs. They travel through the bloodstream primarily from the cancers of the lungs, kidneys, gastrointestinal tract and breast. They become implanted in both the cerebrum and cerebellum and although there is a wide distribution of cancer cells, they are clustered mainly near the surfaces of the brain tissues. Primary brain tumors are more common among children rather than among adults; in children other cancer sites are not likely to have had time to develop to the stage of metastasis required for the transmission of malignant cells to the brain. A cancer that seems to originate in the brain tissues is known as Glioblastoma multiform; a malignant growth hat may strike at any age but is more likely to occur during middle age. The glioblastoma may develop in nearly any part of the brain structure, including the brain stem and spread extensively into a large tumorous mass. Its symptoms include headache, dizziness, nervousness, depression, mental confusion, vomiting and paralysis. The symptoms sometimes are interpreted as those of a psychiatric disorder and treatment of the organic disease may be postponed until too late.
