Primitive Neuroectodermal Tumor
Some cases of primitive neuroectodermal tumor (PNET) show prominent Homer-Wright rosettes as seen here. Like its bone and soft tissue counterparts, the primary renal PNET also demonstrates (in 90% of cases) EWS-FLI1 gene fusion resulting from translocation t(11;22)(q24;q12). FLI1 belongs to the ETS family of transcription factors. Other genes from this family such as ERG, ETV1, E1AF, FEV, and ZSG may also be involved in fusion with EWS.