What exactly is astrocytoma?

Brain tumor: Astrocytoma describes a brain tumor that arises from the cell called the astrocyte in the brain. These are supportive cells that are diffusely located in the normal brain. These tumors can be slow growing or very fast growing and aggressive. The most common type of brain tumor in adults is a type of astrocytoma called a glioblastoma multiforme. These tumors don't go all over the body.