A brain tumor is any intracranial mass created by an abnormal and uncontrolled growth of cells either normally found in the brain itself (neurons, glial cells - astrocytes, oligodendrocytes, ependymal cells, lymphatic tissue, blood vessels), in the cranial nerves (myelin producing cells Schwann cells), in the brain envelopes (meninges), skull, pituitary and pineal gland, or spread from cancers primarily located in other organs (metastatic tumors).
Primary (true) brain tumors are commonly located in the posterior cranial fossa in children and in the anterior two-thirds of the cerebral hemispheres in adults, although they can affect any part of the brain.
In the United States in the year 2000, it was estimated that there were 16,500 new cases of brain tumors1, which accounted for 1.4% of all cancers, 2.4% of all cancer deaths2, and 20%-25% of pediatric cancers2,3. Ultimately, it is estimated that there are 13,000 deaths/year as a result of brain tumors1.
Causes
Aside from exposure to vinyl chloride or ionizing radiation, there are no known environmental factors associated with brain tumors. Mutations and deletions of so-called tumor supressor genes are incriminated in some forms of brain tumors. Patients with various inherited diseases, such as Von Hippel-Lindau syndrome, multiple endocrine neoplasia, neurofibromatosis type 2 are at high risk of developing brain tumors.
Common Cancer Types
|
