CNS tumor with EP300::BCOR fusion: discussing its prevalence in adult population
Arnault Tauziède‐Espariat, Emmanuelle Uro‐Coste, Philipp Sievers, Yvan Nicaise, Cassandra Mariet, Aurore Siegfried, Gaëlle Pierron, Delphine Guillemot, Joseph Benzakoun, Johan Pallud, Margaux Roques, Fabrice Bonneville, Delphine Larrieu‐Ciron, Patrick Chaynes, Raphaël Saffroy, J. HAMELIN, Lauren Hasty, Alice Métais, Fabrice Chrétien, Marcel Kool, Johannes Gojo, Pascale Varlet, RENOCLIP-LOC
Abstract
The Central Nervous System (CNS) tumor with BCOR internal tandem duplication (ITD) has recently been added as a novel embryonal histomolecular tumor type to the 2021 World Health Organization (WHO) Classification of CNS Tumors. In addition, other CNS tumors harboring a BCOR/BCORL1 fusion, which are defined by a distinct DNA-methylation profile, have been recently identified in the literature but clinical, radiological and histopathological data remain scarce. Herein, we present two adult cases of CNS tumors with EP300::BCOR fusion. These two cases presented radiological, histopathological, and immunohistochemical homologies with CNS tumors having BCOR ITD in children. To compare these tumors with different BCOR alterations, we performed a literature review with a meta-analysis. CNS tumors with EP300::BCOR fusion seem to be distinct from their BCOR ITD counterparts in terms of age, location, progression-free survival, tumor growth pattern, and immunopositivity for the BCOR protein. CNS tumors from the EP300::BCOR fusion methylation class in adults may be added to the future WHO classification.