Divergent Genomic Architectures and Immune Microenvironments of BCOR-altered versus YWHAE-rearranged HGESS

High-grade endometrial stromal sarcoma (HGESS) is a rare and aggressive uterine mesenchymal neoplasm characterized by recurrent YWHAE::NUTM2 fusions and BCOR alterations. In this study, we performed integrated genomic and transcriptomic profiling of 45 HGESS and 23 low-grade endometrial stromal sarcoma (LGESS) cases to systematically characterize and compare their clinicopathological features, genomic alterations, transcriptomic profiles, immune microenvironments, and prognostic characteristics, and to explore potential subtype-specific therapeutic opportunities. Among the 45 HGESS cases, 26 underwent targeted DNA panel sequencing and 33 underwent whole-transcriptome sequencing (WTS). Among the 23 LGESS cases, 15 underwent targeted DNA panel sequencing and 11 underwent WTS.