CNS5:Pleomorphic xanthoastrocytoma: Difference between revisions
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!Clinical Relevance Details/Other Notes | !Clinical Relevance Details/Other Notes | ||
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| | |Common chromosome gains: +7, +5, +2, +12, +20, +21, +15 | ||
|Variable; chromosomal hyperdiploidy | |||
|Recurrent (17-20%) | |||
|P | |||
|No | |||
|Whole chromosome gains common; gains of +12 and +21 more common in BRAF V600E tumors; may indicate genomic instability<ref name=":1">Vaubel RA, Caron AA, Yamada S, Decker PA, Eckel Passow JE, Rodriguez FJ, Nageswara Rao AA, Lachance D, Parney I, Jenkins R, Giannini C. Recurrent copy number alterations in low-grade and anaplastic pleomorphic xanthoastrocytoma with and without BRAF V600E mutation. Brain Pathol. 2018 Mar;28(2):172-182. doi: 10.1111/bpa.12495. Epub 2017 Apr 2. PMID: 28181325; PMCID: PMC5807227.</ref> | |||
|- | |- | ||
| | |Whole chromosome loss or cnLOH most commonly involved chromosomes 22, 14, 13, and 10 | ||
|Variable gene losses | |||
| | |Recurrent | ||
| | |P | ||
|< | |No | ||
|Seen in subset; trend toward anaplastic cases<ref name=":1" /> | |||
|- | |- | ||
| | |Complex karyotype with multiple CNVs | ||
| | |Chromosomal instability (CIN) | ||
| | |Common | ||
| | |P | ||
| | |No | ||
| | |Includes polyploidy, subclones, mosaicism; complexity increases at recurrence/progression<ref name=":1" /> | ||
|- | |||
|Pleomorphic xanthoastrocytoma (PXA) not identified as a high‑TMB or focal amplifications. No MSI‑driven marker in PXA. Global mutation pattern in PXA dominated by MAPK activation (BRAF or kinase fusions) plus CDKN2A/B loss | |||
|CDKN2A/B loss and loss of p16/p14ARF tumor suppressors; cell cycle dysregulation | |||
|Common | |||
|P,D | |||
|Yes | |||
|CDKN2A/B loss defining feature of PXA; not associated with grade or BRAF status; central to PXA biology | |||
|} | |} | ||
==Gene Mutations (SNV/INDEL)== | ==Gene Mutations (SNV/INDEL)== | ||