10 year old child with posterior fossa mass. On biopsy following features were seen. What are these dense eosinophilic fibers marked with arrow?
Rosenthal fibers
The Alzheimer type II astrocyte
Corpora amylacea
None
Ans. (a) Rosenthal fibers*Rosenthal fibers are eosinophilic, corkscrew fibers found in pilocytic astrocytoma, the most common primary brain tumor in children. They contain two heat-shock proteins (aB-crystallin and hsp27) as well as ubiquitin.*They are seen in Alexander disease and, pilocytic astrocytoma.
Central Nervous System