Diffuse astrocytoma MYB or MYBL1 altered

Diffuse astrocytoma MYB or MYBL1 altered is a pediatric brain tumor type included in the World Health Organization Classification of Tumors of the Central Nervous System 2021 1).

Differential diagnosis

pediatric-type diffuse low-grade gliomas:

angiocentric glioma

polymorphous low-grade neuroepithelial tumor of the young

diffuse low-grade glioma MAPK pathway-altered

pediatric-type diffuse high-grade gliomas:

diffuse midline glioma, H3 K27-altered

diffuse hemispheric glioma, H3 G34-mutant

diffuse pediatric-type high-grade glioma, H3-wild type, and IDH-wild type

infant-type hemispheric glioma

dysembryoplastic neuroepithelial tumor (DNET)

Specific DNT is a homogeneous group of tumors sharing characteristics of pediatric low-grade gliomas a quiet genome with a recurrent genomic alteration in the RAS-MAPK signaling pathway, a distinct DNA methylation profile, a good prognosis but showing progression in some cases. The “non-specific/diffuse DNTs” subgroup encompasses various recently described histo-molecular entities, such as polymorphous low-grade neuroepithelial tumor of the young and Diffuse astrocytoma MYB or MYBL1 altered 2).

1)
Louis DN, Perry A, Wesseling P, Brat DJ, Cree IA, Figarella-Branger D, Hawkins C, Ng HK, Pfister SM, Reifenberger G, Soffietti R, von Deimling A, Ellison DW. The 2021 WHO Classification of Tumors of the Central Nervous System: a summary. Neuro Oncol. 2021 Aug 2;23(8):1231-1251. doi: 10.1093/neuonc/noab106. PMID: 34185076; PMCID: PMC8328013.
2)
Pagès M, Debily MA, Fina F, Jones DTW, Saffroy R, Castel D, Blauwblomme T, Métais A, Bourgeois M, Lechapt-Zalcman E, Tauziède-Espariat A, Andreiuolo F, Chrétien F, Grill J, Boddaert N, Figarella-Branger D, Beroukhim R, Varlet P. The genomic landscape of dysembryoplastic neuroepithelial tumours and a comprehensive analysis of recurrent cases. Neuropathol Appl Neurobiol. 2022 Jul 14:e12834. doi: 10.1111/nan.12834. Epub ahead of print. PMID: 35836307.