Ewing's sarcoma/peripheral primitive neuroectodermal tumors (ES/pPNET) are a 
group of small round cell sarcomas that show varying degrees of neuroectodermal 
differentiation characterized by translocation involving the EWS gene. Uterine 
ES/pPNET is a rare entity. A 29-year-old Chinese female who presented with 
abdominal swelling and pain was diagnosed with a primary uterine ES/pPNET on the 
basis of clinicopathologic, immunohistochemical and fluorescence in situ 
hybridization (FISH) data. She was given a multimodal treatment, including 
neoadjuvant, 95% cytoreductive, chemotherapy and radiotherapy. The patient is 
currently alive with persistent disease after 18 months of follow-up. We 
emphasized the crucial role of molecular techniques in the differential 
diagnosis of small round cell tumors in this unusual location. Multimodal 
therapy may improve the outcomes of patients.