We focus on the generation of the EWSR1-WT1 fusion using human mesenchymal cells, which is associated with the translocation found in desmoplastic small round cell tumors.
Ewing's sarcoma (ES) and desmoplastic small round cell tumors (DSRCT) are small round blue cell tumors driven by an N-terminal containing EWS translocation.
EWSR1 FISH was sensitive among high-grade round cell sarcomas (positive in 100% of desmoplastic small round cell tumors and 96% of Ewing sarcoma/primitive neuroectodermal tumors) but not specific because clear cell sarcoma, extraskeletal myxoid chondrosarcoma, and a subset of round cell liposarcomas also harbor rearrangements of EWSR1.
Although WT1 immunohistochemistry reflects the EWS-WT1 fusion transcript in most desmoplastic small round cell tumors, some cases express full-length WT1 or have variant transcripts, resulting in atypical staining patterns.
PDGF-A, PDGF-Rbeta, TGFbeta3 and bone morphogenic protein-4 in desmoplastic small round cell tumors with EWS-WT1 gene fusion product and their role in stromal desmoplasia: an immunohistochemical study.
The EWS gene, which maps to band q12 of human chromosome 22, is involved in a wide variety of human solid tumors including Ewing sarcoma, related primitive neuroectodermal tumors, malignant melanoma of soft parts and desmoplastic small round cell tumors.