ABSTRACT
Pilocytic astrocytoma (PA) is the most common pediatric central nervous system (CNS) glial tumor and the most common tumor of the cerebellum in children. The age of presentation is typically in the first two decades of life (peak incidence 5-13 years of age), and clinical signs and symptoms depend on the location of the mass. Patients with cerebellar PA often present with headache, blurred vision, diplopia, neck pain, and gait disturbance. PA in adults occurs more often in the cerebral hemispheres. No gender predilection is known. Other than the cerebellum, PA can also occur in the optic nerve and chiasm, hypothalamic region, cerebral hemispheres, ventricles, velum interpositum, and spinal cord. A well-known asso ciation with neurofibromatosis type 1 exists with PAs seen in the optic pathway. They are World Health Organization (WHO) grade I tumors and generally have
an excellent prognosis with up to 20-year survival of 79%. Hypothalamic PAs carry a less favorable prognosis. Rare instances of metastatic disease have been reported. Surgical resection is the treatment of choice and is often curative. Recurrences are rare. Therapeutic options for PA of the optic nerve/chiasm or hypothalamic region range from conservative to chemotherapy and radiation therapy. Rare instances of spontaneous regression have also been reported.
