???? ??? ?? ?? ? ????? ? ?? ??? ?? ???? ??? ??? ? ??? ? ??? ? ?? ? ??? ??? ??????.????? ? ?? ???? ??? ??? ???? ????? ??? ????? ???? ?????? ???? ?? ?? ????? ???? ? ?? ??? ?????????. ?????.Approximately 87 per cent of Ewing sarcomas are Ewing sarcoma of bone, that is a bone tumor that sometimes takes place during the thigh bones (femurs), pelvis, rib