EWSR1 and Ewing sarcoma: The limitations of this study were as follows: (i) a biopsy should be obtained for histopathological diagnosis to confirm Ewing’s sarcoma after imaging examination; (ii) the use of preoperative chemotherapy may increase the rate of complete surgical resection; and (iii) these genetic changes (EWS and FLI1) can be detected with cytogenetics, fluorescence in situ hybridization, polymerase chain reaction, and gene sequencing.