CNS Tumors Flashcards
(81 cards)

Diffuse Astrocytoma

Rosenthal Fiber
What tumor type are Rosenthal Fibers associated with?
Pilocytic Astrocytoma

Glomeruloid Tufts (in Glioblastoma)

Eosinophilic Granular Body, found in cystic areas of pilocytic, astrocytoma

Cystic cerebellar lesion with a contrast-enhancing mural nodule (Pilocytic Astrocytoma)

Necrotic Glioblastoma

Rosenthal fiber

Pilocytic Astrocytoma - compact and spongy parts

Gemistocytic Variant of Diffuse Astrocytoma

Anaplastic Astrocytoma

Oligodendroglioma
Distinctive features of these glial-derived tumors include round, regularly appearing neoplastic cells without obvious cytoplasmic processing. Note the presence of small, branching, delicate capillary processes in the background. These are so-called “chicken wire capillaries.” Interspersed between tumor cells are small, reactive astrocytes, which are recognizable due to their fine, eosinophilic, cytoplasmic processes.

Oligodendroglioma, Chicken-wire capillaries

Oligodendroglioma with chicken wire capillaries

Green: neuron – prominent nucleolus, large nuclei
Blue: oligodendrocyte – round nuclei, compact chromatin, barely any cytoplasm
Light blue: astrocyte – oval to elongated nuclei, open chromatin, scant prominent eosinophilic cytoplasm

Ependymoma With Rosettes and Canals

Normal Ependymal Lining

Ependymoma

Pilocytic Astrocytoma (from wikipedia)

Perivascular pseudorosette
This rosette consists of tumor cells collected around a blood vessel. It’s called a pseudorosette because the central structure isn’t part of the tumor. In the past, the term pseudorosette meant any rosette that didn’t have a truly empty lumen…but it seems that designation is kind of outdated. These rosettes are common in ependymomas, but you also see them in medulloblastoma, PNET, central neurocytomas, and glioblastomas.

True Rosette
This rosette (seen in ependymoma) consists of tumor cells surrounding an empty lumen. It is thought that these structures represent attempts by the tumor cells to recreate little ventricles with ependymal lining. One thing to note: although these guys are characteristic of ependymoma, they’re not seen in every case. In fact, it’s fairly uncommon to find them at all (they’re only present in a small percentage of well-differentiated ependymoma).

Perivascular pseudorosette, Ependymoma

Homer Wright Rosette
This rosette, named for James Homer Wright, the first director of the Massachusetts General Hospital, is typically seen in neuroblastomas, medulloblastomas, and primitive neuroectodermal tumors (PNETs). It consists of a halo of tumor cells surrounding a central region containing neuropil (hence its association with tumors of neuronal origin).

Medulloblastoma
























