Ependymal rosettes (ependymoma)
Ependymal rosettes correspond to a histologic architectural pattern that very characteristic of ependymomas, as tumor cells form structures similar to the lining of normal ventricles. They are characterized by a halo or spoke-wheel arrangement of tumor cells surrounding an empty central tubule lumen.
They should not be confused with the far more common perivascular pseudorosettes.
Differential diagnosis
In addition to perivascular pseudorosettes, an ependymal rosette should be differentiated from:
- Homer Wright rosette: central lumen filled with fiber-like processes
- Flexner-Wintersteiner rosette: central lumen contains small cytoplasmic extensions of the encircling cells
- pineocytomatous and neurocytic rosettes: generally larger and more irregular in contour
Related Radiopaedia articles
Histology
- cells (general)
- general cellular structure
- cell membrane
- nucleus
- nucleolus
- chromatin
- cytoplasm
- organelles
- cytoskeleton
- endoplasmic reticulum
- smooth
- rough
- Golgi complex
- lysosomes
- mitochondria
- peroxisomes
- ribosomes
- body systems
- general cellular structure
- immunohistochemistry
-
histological stains
- alcian blue stain
- azan stain
- Giemsa stain
- Gram stain
- hematoxylin and eosin stain (H&E)
- immunoperoxidase staining
- Luxol fast blue stain
- Masson's trichrome stain
- methylene blue
- Nissl stain
- oil red O stain
- osmium stain
- Papanicolaou stain
- periodic acid-Schiff reaction (PAS)
- Prussian blue stain
- reticulin stain
- silver stain
- Sudan stains
- toluidine blue stain
- van Gieson stain
- Ziehl-Neelsen stain
- regions
- specific features and structures