What is a pleomorphic astrocytoma?
Pleomorphic xanthoastrocytoma (PXA) is a rare, benign brain tumor that likely arises from astrocytes, cells in the nervous system that make up the supportive network for the brain. It is an astrocytoma, which is a type of glioma. Pleomorphic xanthoastrocytoma typically occurs in the cerebral hemisphere, the uppermost sections of the brain and the leptomeninges, one of the layers covering the brain. Rarely it develops in the spinal cord. Pleomorphic xanthoastrocytomas affect males and females equally — the average age of diagnosis is 12 years. Very rarely, a PXA will transform into a more malignant tumor.
What are the symptoms of pleomorphic xanthoastrocytoma?
The most common symptom of PXA at diagnosis is the sudden onset of seizure activity. In fact, nearly 70 percent of children diagnosed with these tumors have seizures. Other, less common symptoms include:
- signs of intracranial pressure, such as headache
- hemiparesis (weakness on one side of the body)
- change in behavior
These tumors, which often occur in children and teenagers, appear to develop spontaneously.
How we care for pleomorphic xanthoastrocytoma
Children and adolescents with pleomorphic xanthoastrocytoma (PXA) are treated at Dana-Farber/Boston Children's Cancer and Blood Disorders Center through our Glioma Program, one of the largest and most experienced pediatric glioma programs in the world, and part of the Dana-Farber/Boston Children’s Brain Tumor Center.
Our glioma specialists — a team of neuro-oncologists, surgeons, pathologists and radiation oncologists — focus solely on the care of children diagnosed with gliomas. The Glioma Program also offers families the chance to have their child's tumor molecularly profiled (as long as a biopsy can be taken), which may help identify opportunities for targeted treatment.
Pleomorphic Xanthoastrocytoma | Diagnosis & Treatments
How is pleomorphic xanthoastrocytoma diagnosed?
Diagnostic procedures for a pleomorphic xanthoastrocytoma (PXA) may include:
- physical examination
- computerized tomography scan (CT or CAT scan)
- magnetic resonance imaging (MRI)
- electroencephalogram (EEG)
After all tests are completed, doctors will be able to outline the best treatment options.
What are the treatment options for pleomorphic xanthoastrocytoma?
The following treatments may be used alone or in combination to treat PXA:
- radiation therapy may be considered, but does not influence long-term outcomes.
- biologic therapy
Researchers at Dana-Farber/Boston Children's Cancer and Blood Disorders Center have discovered a mutation that occurs in over half of all patients with PXA and there are now new drugs that target this mutation available. There can be side-effects related to the tumor itself or its treatment. Knowing what these side effects are can help physicians prepare for and, in some cases, prevent these symptoms from occurring.
Progressive or recurrent disease
Recurrences can happen with PXAs. Radiation therapy should be considered for patients with recurrent disease whose tumor has been completely removed. If disease recurs in patients whose tumors have been incompletely removed, a second attempt at surgical removal is usually performed.