Astrocytomas develop from small, star-shaped cells called astrocytes, and may arise anywhere in the brain or spinal cord. Astrocytomas are the most common primary CNS tumor. In adults, astrocytomas most often occur in the cerebrum, which is the largest part of the brain.
The cerebrum uses sensory information to tell us what’s going on around us and how our body should respond. The left hemisphere controls the muscles on the right side of the body, while the right hemisphere controls the muscles on the left. The cerebrum also controls speech, movement and emotions, as well as reading, thinking and learning.
Overview of astrocytomas
- Grade I: Pilocytic astrocytoma
- Grade II: Diffuse astrocytoma / Low-grade astrocytoma
- Grade III: Anaplastic astrocytoma
- Grade IV: Glioblastomas (also called glioblastoma multiforme, GBM, or grade IV astrocytoma). Anaplastic astrocytomas and glioblastomas are malignant astrocytomas that grow and spread aggressively, accounting for more than 50 percent of all astrocytomas. Glioblastomas occur most often in adults between the ages of 50 and 70.
- Brain stem gliomas arise in the brain stem, which controls many vital functions, such as body temperature, blood pressure, breathing, hunger and thirst. The brain stem also serves to transmit all the signals to the body from the brain. The brain stem is in the lowest part of the brain, and connects the brain and spinal cord. Tumors in this area can be difficult to treat. Most brain stem gliomas are high-grade astrocytomas.