Astrocytomas are glial cell tumors that are derived from connective tissue cells called astrocytes. These cells can be found anywhere in the brain or spinal cord. Astrocytomas are the most common type of childhood brain tumor. Astrocytomas are generally subdivided into high-grade, medium-grade or low-grade tumors. High-grade astrocytomas are the most malignant of all brain tumors. Astrocytomas are further classified for presenting signs, symptoms, treatment, and prognosis, based on the location of the tumor. The most common location of these tumors is in the cerebellum, where they are called cerebellar astrocytomas. These tumors usually cause symptoms of increased intracranial pressure, headache, and vomiting. There can also be problems with walking and coordination, as well as double vision.