Detection of EWS-WT1 fusion transcripts in paraffin-embedded tissues for desmoplastic small round cell tumor

Objective: To detect the EWS-WT1 chimeric mRNA in desmoplastic small round cell tumor (DSRCT) and its clinicopathological significance.

Methods: Formalin fixed, paraffin-embedded tumor specimens from 4 examples of this entity were studied by reverse transcriptase polymerase chain reaction to detect the EWS-WT1 fusion transcripts resulting from the chromosomal translocation t(11;22)(p13;q12). The following tumor specimens were included as controls: 2 Ewing's sarcomas/primitive neuroectodermal tumors (PNET/ES), 2 alveolar rhabdomyosarcomas, and 2 lymphomas.

Results: EWS-WT1 fusion transcripts were detected in 3 of 4 desmoplastic small round cell tumors but not in any other tumor types studied as controls.

Conclusions: The analysis of the EWS-WT1 fusion transcript which was performed on formalin-fixed, paraffin-embedded tissues is a sensitive and specific method in the diagnosis and differential diagnosis of DSRCT.