- Summary of CNS tumors with Rosette formation.
| Tumor type | Age | Location | Morphology | Positive antibodies |
|---|---|---|---|---|
| Ependymoma GII, GIII | Children/ young adults | Wall of the ventricles Spinal canal | -Uniform round to oval cells with salt and pepper chromatin.- Perivascular pseudorosettes >true | GFAP S100 EMA dot and ring |
| Astroblastoma | Children/ young adults | Cerebrum | - Astroblastic pseudorosettes- “stout” - (not fibrillar) processes - Prominent vascular hyalinization. | GFAP S100EMA focal cytoplasmic or dotlike |
| Rosettes forming glioneuronal tumor G1 | Young adults | 4th ventricle Cerebellum | Biphasic:-- Neuronal component: small uniform cells forming neurocytic true or pseudorossettes.– Glial component: pilocytic astrocytoma or oligodendroglioma like | Neurocytic rosettes: SynaptophysinNeuNGlial component:GFAP S100 |
| Medulloblastoma GIV | Children | Cerebellum | - Small round blue cell tumor- Brisk mitotic activity- Prominent karyorrhexis- Homer Wright rosettes | Synaptophysin B-catenin CMYC P53 YAPGAB |
| Embryonal tumor with multilayered rosettes / NOS GIV | Children | Cerebrum Brain stem Cerebellum | 3 histological patterns in ETMR:- Embryonal tumor with abundant neuropil and true rosettes (ETANTR)– Medulloepithelioma– Ependymoblastoma | Synaptophysin C19MC altered |
| Pineoblastoma GIV | Children | Pineal gland | - Small round blue cell tumor-Homer Wright rosettes- Flexner–Wintersteiner rosettes | Synaptophysin |
| Pituitary adenoma | Adults | Pituitary gland | - Uniform nuclear morphology- Abundant cytoplasm- Perivascular rosettes - Papillae | Synaptophysin Pit. Hormones Transcription factor |