Brain Cancer, Infornation of Brain Cancer

Tumor Grade

Doctors sometimes group brain tumors by grade—from low grade (grade I) to high grade (grade IV). The grade of a tumor refers to the way the cells look under a microscope. Cells from high-grade tumors look more abnormal and generally grow faster than cells from low-grade tumors
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Primary Brain Tumors

Tumors that begin in brain tissue are known as primary tumors of the brain. (Information about secondary brain tumors appears in the following section.) Primary brain tumors are named according to the type of cells or the part of the brain in which they begin.
The most common primary brain tumors are gliomas. They begin in glial cells. There are many types of gliomas:

·         Astrocytoma—The tumor arises from star-shaped glial cells called astrocytes. In adults, astrocytomas most often arise in the cerebrum. In children, they occur in the brain stem, the cerebrum, and the cerebellum. A grade III astrocytoma is sometimes called an anaplastic astrocytoma. A grade IV astrocytoma is usually called a glioblastoma multiforme.

·         Brain stem glioma—The tumor occurs in the lowest part of the brain. Brain stem gliomas most often are diagnosed in young children and middle-aged adults.

·         Ependymoma—The tumor arises from cells that line the ventricles or the central canal of the spinal cord. They are most commonly found in children and young adults.

·         Oligodendroglioma—This rare tumor arises from cells that make the fatty substance that covers and protects nerves. These tumors usually occur in the cerebrum. They grow slowly and usually do not spread into surrounding brain tissue. They are most common in middle-aged adults.