Alexander Disease, H&E stained s

All these red blobs, like the one indicated by the unnecessarily large green arrow, are "Rosenthal fibers." Rosenthal fibers are eosinophilic, intracytoplasmic inclusions seen in reactive tissue, neoplasms like pilocytic astrocytoma, and in Alexander disease. Rosenthal fibers are comprised of a combination of compounds, including ubiquitin, some small heat shock proteins, and GFAP or something akin to it.