Merck Manual

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Kee Kiat Yeo

, MD, Harvard Medical School

Reviewed/Revised Jan 2023

Astrocytomas are central nervous system tumors that develop from astrocytes. Diagnosis is based on MRI. Treatment is a combination of surgical resection and chemotherapy. Radiation therapy is rarely used to treat low-grade tumors but is commonly used to treat high-grade tumors.

Astrocytes are star-shaped glial cells that form a large portion of the brain parenchyma and serve various functions depending on their location in the central nervous system. Astrocytomas range from low-grade indolent tumors (the most prevalent) to malignant high-grade tumors.


  • 1. Ostrom QT, Price M, Neff C, et al: CBTRUS statistical report: Primary brain and other central nervous system tumors diagnosed in the United States in 2015-2019. Neuro Oncol 24(Suppl 5):v1–v95, 2022. doi: 10.1093/neuonc/noac202

  • 2. Jones C, Perryman L, Hargrave D: Paediatric and adult malignant glioma: Close relatives or distant cousins? Nat Rev Clin Oncol 9(7):400–413, 2012. doi: 10.1038/nrclinonc.2012.87

  • 3. Greuter L, Guzman R, Soleman J: Pediatric and adult low-grade gliomas: Where do the differences lie? Children (Basel) 8(11):1075, 2021. doi: 10.3390/children8111075

Symptoms and Signs of Astrocytomas

Most patients have symptoms consistent with increased intracranial pressure (eg, morning headaches, vomiting, lethargy). Location of the tumor determines other symptoms and signs, for example

  • Cerebellum: Weakness, tremor, and ataxia

  • Cerebral hemispheres: Weakness, numbness, or seizures

  • Visual pathway: Visual loss, proptosis, or nystagmus

  • Spinal cord: Pain, weakness, and gait disturbance

Diagnosis of Astrocytomas

  • Contrast-enhanced MRI

  • Biopsy

Contrast-enhanced MRI is the imaging test of choice for diagnosing the tumor, determining extent of disease, and detecting recurrence. Contrast-enhanced CT can also be used, although it is less specific and less sensitive.

With exceptions, biopsy is needed for determining tumor type and grade. These tumors are typically classified as low grade (eg, pilocytic astrocytoma) or high grade (eg, anaplastic astrocytoma). Many pathologists designate grades 1 and 2 tumors as low grade and grades 3 and 4 tumors as high grade.

Treatment of Astrocytomas

  • Surgical resection

  • Sometimes radiation therapy and/or chemotherapy

Treatment of astrocytoma depends on location and grade of tumor. As a general rule, the lower the grade of the tumor, the less intensive the therapy and the better the outcome.

Low-grade astrocytomas

Surgical resection is the primary treatment, and total resection is the goal (if safe). Even after local recurrence, a second surgical resection can be beneficial depending on the location of the tumor.

Chemotherapy is generally used, when treatment is needed, for children whose tumors are unresectable, cannot be completely excised, or progress/recur after surgery.

Radiation therapy is rarely used in children with low-grade astrocytoma because of the associated long-term cognitive impairment.

Most children with low-grade astrocytomas have an excellent overall outcome and are long-term survivors.

High-grade astrocytomas

These tumors are treated with a combination of surgery (unless location precludes it), radiation therapy, and chemotherapy. The role of chemotherapy is unclear.

Treatment reference

  • 1. Cohen KJ, Pollack IF, Zhou T, et al: Temozolomide in the treatment of high-grade gliomas in children: A report from the Children's Oncology Group. Neuro Oncol 13(3):317–323, 2011. doi: 10.1093/neuonc/noq191

More Information

The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

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