 Endometrial stromal sarcoma (ESS) characterized by YWHAE-FAM22 genetic fusion is histologically higher grade and clinically more aggressive than ESS with JAZF1-SUZ12 or equivalent genetic rearrangements, hence it is clinically important to recognize this subset of ESS.     ///    These studies showed consistent upregulation of cyclin D1 in YWHAE-FAM22 ESS compared with JAZF1-SUZ12 ESS. 