The aim of this study was to explore by RNA sequencing a retrospective series of uterine sarcomas diagnosed as endometrial stromal sarcomas but negative for JAZF1 and/or YWHAE rearrangement in FISH, in order to provide a better description of their molecular landscape, improve the classification of endometrial stromal sarcomas and provide guidance for disease management. Here, YWHAE is linked to endometrioid stromal sarcoma.