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What is 10 year old child with posterior fossa mass. On biopsy following features were seen. What are these dense eosinophilic fibers marked with arrow? and explain in detail?
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.