Master Pilocytic Astrocytoma with Picmonic for Medicine

This tumor is typically found in the posterior fossa, which is located between the foramen magnum and tentorium cerebella. This region contains the brainstem and the cerebellum.

The cerebellum is the most common location of pilocytic astrocytomas.

These tumors tend to be slow growing and well circumscribed with very little infiltration into surrounding structures.

Glial fibrillary acidic protein is an intermediate filament protein expressed by certain cell types of the CNS including astrocytes and ependymal cells. Because they stain for astrocytes, pilocytic astrocytomas stain positive for GFAP, which can help with tumor identification.

On histologic examination, Rosenthal fibers can be visualized, which are thick, eosinophilic corkscrew fibers. These fibers are thought to be bunched intermediate filament proteins that are found in astrocytic processes.

On histologic examination, Rosenthal fibers can be visualized, which are thick, eosinophilic corkscrew fibers. These fibers are thought to be bunched intermediate filament proteins that are found in astrocytic processes.