This Tumours has a peak age at onset in adolescence, is rare in black races, and is not radiation induced. Its incidence is 1.7 per 1,000,000 per year. Familial cases are rare, and the Tumours only rarely occurs as part of specific familial cancer syndromes. It is probably a member of a family of neoplasms that includes a skin Tumours and primitive neuroectodermal Tumours of bone and soft tissue. Retinoblastoma has been recorded as a first primary cancer in ten cases of Ewing sarcoma, and Ewing sarcoma has also occurred after leukemia and lymphoma (Coppes et al. 2001). An excess of inguinal hernias has been observed in children with Ewing sarcoma.
A t(11; 22)(q24; q12) translocation occurs in up to 95 % of Ewing sarcomas and also in primitive neuroectodermal Tumours and in peripheral neuroepithelioma and Askin Tumours. Some Ewing sarcomas without a t(11;22) show more complex rearrangements or rearrangements involving 22q12 and other chromosomes so that, overall, 92 % of Tumours have a 22q12 breakpoint and 88 % have a 11q23.3 breakpoint (Griffin et al. 1986). A der (16) t(1; 16)(q11; q11) has been observed in the later stages of Tumours development (Mugneret et al. 1987). The result of the t(11; 22) is that an aberrant transcription factor protein is produced (Granwetter 1995; Lin et al. 1999). None of these genetic rearrangements are inherited.