An 8-year-old boy undergoes a resection of a tumor in the right cerebrum next to the lateral ventricle (supratentorial). The pathologist feels the histology is most consistent with an ependymoma. The tumor is sent for advanced molecular and genetic testing. Which of the following findings would further support a diagnosis of ependymoma?
Correct Answer: C
Rationale: The correct answer is C: RELA fusion. Ependymomas are known to have specific molecular characteristics, with RELA fusion being a common genetic alteration associated with these tumors. The fusion of RELA gene is a key genetic event in the pathogenesis of supratentorial ependymomas. This fusion leads to the activation of the NF-κB signaling pathway, which is important in the development and progression of ependymomas.
Now, let's summarize why the other choices are incorrect:
A: BRAFKIAA1549 fusion - This fusion is typically associated with pilocytic astrocytomas, not ependymomas.
B: BRAFV600E mutation - This mutation is commonly found in other types of brain tumors like pleomorphic xanthoastrocytomas and gangliogliomas, not ependymomas.
D: H3K27M mutation - This mutation is typically seen in diffuse midline gliomas, such as diffuse