Table 1

- Summary of CNS tumors with Rosette formation.

Tumor typeAgeLocationMorphologyPositive antibodies
Ependymoma GII, GIIIChildren/ young adultsWall of the ventricles Spinal canal-Uniform round to oval cells with salt and pepper chromatin.- Perivascular pseudorosettes >trueGFAP S100 EMA dot and ring
AstroblastomaChildren/ young adultsCerebrum- Astroblastic pseudorosettes- “stout” - (not fibrillar) processes - Prominent vascular hyalinization.GFAP S100EMA focal cytoplasmic or dotlike
Rosettes forming glioneuronal tumor G1Young adults4th ventricle CerebellumBiphasic:-- Neuronal component: small uniform cells forming neurocytic true or pseudorossettes.– Glial component: pilocytic astrocytoma or oligodendroglioma likeNeurocytic rosettes: SynaptophysinNeuNGlial component:GFAP S100
Medulloblastoma GIVChildrenCerebellum- Small round blue cell tumor- Brisk mitotic activity- Prominent karyorrhexis- Homer Wright rosettesSynaptophysin B-catenin CMYC P53 YAPGAB
Embryonal tumor with multilayered rosettes / NOS GIVChildrenCerebrum Brain stem Cerebellum3 histological patterns in ETMR:- Embryonal tumor with abundant neuropil and true rosettes (ETANTR)– Medulloepithelioma– EpendymoblastomaSynaptophysin C19MC altered
Pineoblastoma GIVChildrenPineal gland- Small round blue cell tumor-Homer Wright rosettes- Flexner–Wintersteiner rosettesSynaptophysin
Pituitary adenomaAdultsPituitary gland- Uniform nuclear morphology- Abundant cytoplasm- Perivascular rosettes - PapillaeSynaptophysin Pit. Hormones Transcription factor