<unk> s are a type of brain tumor. They originate in a particular kind of glial cells, star-shaped brain cells in the cerebrum called astrocytes. This type of tumor does not usually spread outside the brain and spinal cord and it does not usually affect other organs.<unk> s are the most common glioma and can occur in most parts of the brain and occasionally in the spinal cord. Within the<unk> s, two broad classes are recognized in literature, those with: * Narrow zones of infiltration (mostly noninvasive tumors; e.g., pilocytic<unk> , subependymal giant cell<unk> , pleomorphic xanthoastrocytoma), that often are clearly outlined on diagnostic images * Diffuse zones of infiltration (e.g., high-grade<unk> , anaplastic<unk> , glioblastoma), that share various features, including the ability to arise at any location in the central nervous system, but with a preference for the cerebral hemispheres; they occur usually in adults, and have an intrinsic tendency to progress to more advanced grades. People can develop<unk> s at any age. The low-grade type is more often found in children or young adults, while the high-grade type is more prevalent in adults.<unk> s in the base of the brain are more common in young people and account for roughly 75% of neuroepithelial tumors.
Astrocytoma
Oligoastrocytoma
Hemangiopericytoma
Ameloblastoma
Schwannoma
Glioma
Schwannomatosis
Hemangioblastoma