Pilocytic Astrocytoma

Comments:
Higher magnification showing piloid fibers in a pilocytic astrocytoma. On imaging studies and in gross specimens, the tumor is usually well-circumscribed and has cystic and solid areas. Microscopically, there is usually some infiltration at the edges of the tumor. The tumor nuclei are oval with bland chromatin. Occasional cases may show degenerative-type atypia. Mitotic activity is not increased.