Читать книгу The SAGE Encyclopedia of Stem Cell Research - Группа авторов - Страница 188

An abnormal and uncontrolled division of cells in the brain can result in brain cancer. A clinically detectable tumor contains a heterogeneous population of cells, which originate from clonal growth of the progeny of a single cell. Brain cancers are of two types. Primary cancers are the tumors that arise within the brain parenchyma or the structures related to it. Secondary cancers metastasize from somewhere else in the body. These can be malignant (containing cancerous cells) or benign (containing noncancerous cells). Benign cancers grow slowly and have low mitotic activity, uniformity, well-defined borders, and rarely spread. Malignant cancers, on the other hand, grow rapidly and are invasive or infiltrative. However, the distinction between the benign and malignant lesion is less evident in the central nervous system (CNS). Brain cancers can cause a variety of symptoms by interfering with the normal functions of the brain. These symptoms mainly depend upon the type, location, and extent of the tumor. Different treatment modalities are available depending upon the grade, stage, and effects of the tumor.