Find a summary of molecular alterations in ependymoma
SOME MCQs RELATED TO THE SUMMARY
- Shown in the image is an L1CAM immunostain in an ependymoma. Which of the following is true about this entity?
- The histologic features correspond to anaplastic ependymoma, WHO grade III
- The immunohistochemical stain is confirmed by FISH
- This immunophenotype is characteristic of posterior fossa ependymomas
- This immunophenotype may not be seen in central neurocytoma, anaplastic astrocytoma and primitive neuronal tumors
Answer to Question 1
B. The immunohistochemical stain is confirmed by FISH- IHC positivity is often confirmed using FISH
Cytoplasmic immunopositivity for L1CAM is characteristic of supratentorial – ZFTA fusion ependymomas.
Option A: ZFTA-fused supratentorial ependymomas show varying ependymoma AND degrees of anaplasia and have been regarded as CNS WHO grade 2 or 3 on this basis.
Option C: ZFTA- fused ependymomas are often supratentorial and not posterior fossa
Option D: L1CAM Positivity id also seen in
- Olfactory neuroblastoma
- Central neurocytoma
- Primitive neuronal tumors
Reference : WHO CNS Tumors 5th edition page no 165
Which of the following combinations of ependymoma molecular subtype and clinical characteristics is correct?
- Posterior fossa ependymoma, subtype A / supratentorial / poor
- Spinal myxopapillary ependymoma / supratentorial / good
- Supratentorial ependymoma, RELA / children / poor
- Supratentorial ependymoma, YAP1 / adults / good
Answer to question 2
C. Supratentorial ependymoma, RELA / children / poor
RELA fusion ependymomas are now classified under ZFTA fusion under latest WHO 5th edition
|Molecular subtype of ependymoma||Site||Age||Prognosis|
|ZFTA fusion||Supratentorial||Both children and adults||Poor|
|YAP 1 fusion||Supratentorial||Both children and adults||Good|
|Posterior fossa A||Posterior fossa||Predominantly children||Poor|
|Posterior fossa B||Posterior fossa||Predominantly children||Good|
Reference : WHO CNS Tumors 5th edition page no 159