We report an unusually aggressive case of ES with an EWS-ERG fusion gene that appeared to be a result of a simple balanced and reciprocal translocation, t(19;22)(q13.2;q12.2).     ///     EWS-ERG Ewing sarcoma (ES) gene fusions often result from complex chromosomal rearrangements.     ///    "Complex rearrangement of chromosomes 19, 21, and 22 in Ewing sarcoma involving a novel reciprocal inversion-insertion mechanism of EWS-ERG fusion gene formation: a case analysis and literature review.. "    ///    "Molecular cytogenetic investigation, using systematic analysis with locus-specific probes, identified the cognate genomic breakpoints within chromosome 21 and 22, mandatory for the excision and exchange of both 3'ERG and 3'EWS, resulting in the formation of the EWS-ERG fusion gene present on the der(22). "    ///    "Subsequent molecular investigation of the primary tumor, the metastasis, and a cell line generated from this ES permitted reconstruction of each genomic step in the evolution of this complex EWS-ERG fusion. "