Other CNS embryonal tumours
| Other CNS embryonal tumours | |
|---|---|
| Diagnosis in short | |
 Other CNS embryonal tumorH&E stain. | |
|
| |
| Synonyms | CNS-PNET |
| LM DDx | small round blue cell tumours |
| IHC | S-100 +ve, Syn +/-ve |
| Site | brain, spinal cord |
|
| |
| Prevalence | rare - typically in children and young adults |
| Prognosis | poor (WHO Grade IV) |
Other CNS embryonal tumor, was introduced in the WHO 2016 classification of CNS tumors. Some of these tumors of this category has been previously designated as CNS-PNET but this terminology has been abandoned.
General
Other CNS embryonal tumours are a group of primitive neuroeptithelial tumors that are to be classified in distinct molecular groups in the future. Currently it is a exlcusion criteria encompassing four subgroups
- CNS neuroblastomas
- CNS ganglioneuroblastomas.
- often characterized by FOXR2 fusions: CNS neuroblastoma with FOXR2 activation (NB‐FOXR2)
- CNS medulloepithelioma.
- but absence of C19MC alteration, otherwise classified as ETMR
- CNS embryonal tumour, NOS
- Similarities to astroblastoma: High‐grade neuroepithelial tumours with MN1 alteration (HGNET‐MN1)
- NUTM1-positive IHC: Ewing's sarcoma family tumour with CIC alteration (EFT‐CIC)
- BCOR-positive IHC: HGNET BCOR‐altered neuroepithelial tumours
IHC
CNS Ganglioneuroblastoma + Neuroblastoma
- Syn -/+ve.
- Vim -ve.
- GFAP usu -ve.
- MIB-1 usu high.
Medulloepthelioma
DDx:
- AT/RT
- ETMR
- Anaplastic ependymoma
- H3F3A G34-mutated Glioblastoma