WT1 and desmoplastic small round cell tumor: A diagnosis of desmoplastic small round cell tumor (DSRCT) was favored initially.7 Because EWSR1 breakapart fluorescence in situ hybridization confirmed an EWSR rearrangement but concomitant WT1 breakapart fluorescence in situ hybridization was negative, the molecular criterion for DSRCT was not met, and a final diagnosis of poorly differentiated sarcoma, not otherwise specified, was rendered.