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.
As a group, astrocytomas are the most common central nervous system tumor in children, representing approximately 40% of pediatric central nervous system tumors (1). Most cases occur between the ages of 5 years and 9 years. These tumors can occur anywhere in the brain or spinal cord but are most common in the cerebellum.
Despite similarities in appearance, astrocytomas in children and adults have different biological backgrounds with different molecular findings, leading to differences in clinical features such as where the tumors arise, how they are treated, and overall outcomes (2, 3).
References
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.
Prognosis is poor; overall survival at 3 years is only 20 to 30% (1).
Treatment reference
1. Cohen KJ, Pollack IF, Zhou T, et alNeuro 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.
World Health Organization (WHO): The 2021 WHO Classification of Tumors of the Central Nervous System: A summary
