What is pilocytic astrocytoma?

➢ Typically affect children and young adults. ➢ Most commonly located in the cerebellum, they also may involve the third ventricle, the optic pathways, the spinal cord, and occasionally the cerebral hemispheres ➢ Relatively benign tumors ➢ Have a very good prognosis after surgical removal. ➢These are often slow-growing, low-grade astrocytic tumors that are minimally infiltrative ➢ On MRI, the the typical appearance of a pilocytic astrocytoma is that of a large cerebellar cyst with a small mural nodule ➢ Pilocytic cells with long thin processes that are GFAP positive, similar to cells of other gliomas, Red Rosenthal fibers ➢ Tumor cells often contain Rosenthal fibers and eosinophilic granular bodies. ➢ PAs are highly vascular and enhance with contrast injection. Most PAs are biologically low grade and do not evolve into more malignant tumors. ➢ Surgical excision of cerebellar PA (even partial resection in some instances) sometimes results in permanent cure