Summary

• Circumscribed astrocytic tumours (pleomorphic xanthoastrocytoma, subependymal giant cell astrocytoma, pilocytic astrocytoma) have well-defined margins, are benign, and can be cured with surgery alone.
• Diffuse astrocytomas (grade II to IV) represent a spectrum of the same highly infiltrative disease, with lower grades inevitably progressing to higher grade. They share common molecular genetic abnormalities.
• Low-grade astrocytomas (grade I and II) tend to be present in younger patients and have a better prognosis.
• High-grade astrocytomas (grade III and IV) present in older patients, and the prognosis is dismal.
• There are no known predisposing factors except rare familial syndromes and prior radiotherapy.
• Treatments vary depending on grade, and include surgery alone or in combination with radiotherapy and/or chemotherapy.