By combining clinical setting, disease presentation, histologic/cytologic features, immunohistochemistry, and fluorescence in situ hybridization studies (using dual color, break-apart probes for the EWSR1 gene) it is possible to specifically diagnose DSRCT and to exclude EW/PNET, as was historically done in this case [2]. The gene discussed is EWSR1; the disease is desmoplastic small round cell tumor.