HG-ESS with YWHAE-NUTM2 fusion have strong nuclear cyclin D1 expression, which is found rarely – if at all – in other subtypes of ESS, and is likewise uncommon in other gynecologic sarcomas that can enter the differential diagnosis of HG-ESS, such as leiomyosarcoma1,9. This evidence concerns the gene CCND1 and endometrioid stromal sarcoma.