Astrocytomas are neoplasms of the brain that originate in a particular kind of glial-cells: the star-shaped brain cells called astrocytes. This type of tumor doesn't usually spread outside the brain and spinal cord and it doesn't usually affect other organs. Astrocytomas are the most common glioma, and can occur in most parts of the brain and occasionally in the spinal cord. Astrocytomas originate from cells called astrocytes and are most commonly found in the main part of the brain, the cerebrum.
Within the Astrocytomas broadly two classes are recognized in literature :
- those with narrow zones of infiltration (mostly invasive tumors; e.g., pilocytic astrocytoma, subependymal giant cell astrocytoma, pleomorphic xanthoastrocytoma), that often are clearly outlined on diagnostic images
- those with diffuse zones of infiltration (e.g., low-grade astrocytoma, anaplastic astrocytoma, glioblastoma), that share various features, including the ability to arise at any location in the CNS, but with a preference for the cerebral hemispheres; they occur usually in adults; and an intrinsic tendency to progress to more advanced grades.
People can develop astrocytomas at any age, the low grade type is more often found in children or young adults the high graded kinds are more prevalent in adults. Astrocytomas in the base of the brain are more common in young people. They account for roughly 75% of neuroepithelial tumors.
