ASTROCYTOMA

DEFINITION

Astrocytomas are primary intracranial tumors derived from astrocyte cells of the brain. They may arise in the cerebral hemispheres, in the posterior fossa, in the optic nerve, and rarely, the spinal cord. In almost half of the cases, the first symptom of an astrocytoma is the onset of a focal or generalized seizure. Between 60 to 75% of patients will have recurrent seizures in the course of their illness. Headache and signs of increased intracranial pressure (headache, vomiting) usually present late in the disease course. A Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) scan is necessary to characterize the anatomy of this tumor (size, location, consistency). Resection of tumors will generally allow functional survival for many years.

In recent reports, the 5 year survival has been over 90% with well resected tumors. These tumors may eventually undergo malignant transformation in which case radiation therapy or chemotherapy may be necessary. Astrocytomas often recur even after treatment and are usually treated similarly as the initial tumor, with sometimes more aggressive chemotherapy or radiation therapy. In some rare cases, the tumor creates two or more cell types, and treatment may kill one cell type while allowing the other to become more aggressive and immune to future treatments.

In children, the tumor is usually located in the cerebellum and will present with some combination of vision deterioration (which is typically uncorrectable by glasses), gait instability, unilateral ataxia, and signs of increased intracranial pressure (headache, vomiting). Children with astrocytoma usually have decreased memory, attention, and motor abilities, but unaffected intelligence, language, and academic skills. When metastasis occurs, it can spread via the lymphatic system, causing death even when the primary tumor is well controlled.

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