A glioma is a type of tumor that originates from glial cells in the nervous system, specifically in the brain or spinal cord. Glial cells are the supportive cells that help nourish, protect, and support neurons, which are the primary cells responsible for transmitting signals in the nervous system. Gliomas are primary tumors, meaning they start in the nervous system rather than spreading from elsewhere in the body. They can be malignant (cancerous) or low-grade (slow-growing and less aggressive). Gliomas comprise about 30% of all brain and central nervous system tumors and about 80% of all malignant brain tumors. There are several types of gliomas, classified based on the specific type of glial cell they develop from:
- Astrocytomas: arising from star-shaped glial cells called astrocytes; the most common type.
- Glioblastomas: an aggressive form of astrocytoma.
- Oligodendrogliomas: originating from oligodendrocytes, which are cells that produce myelin to insulate nerve fibers.
- Ependymomas: tumors from ependymal cells lining the brain's ventricles and spinal canal.
- Brainstem gliomas: tumors developing in the brainstem.
- Optic nerve gliomas: affecting the optic nerve.
Symptoms of gliomas depend on their location and may include headaches, seizures, memory loss, vision problems, speech difficulties, weakness, numbness, and coordination problems. Treatment often involves a combination of surgery, radiation therapy, and chemotherapy, with the approach and prognosis depending on the glioma's type and grade (how aggressively it grows). In summary, a glioma is a tumor of the nervous system that arises from the supportive glial cells in the brain or spinal cord, with varied types and severity affecting symptoms and treatment options.
