Ewing's sarcoma is a rare type of cancer that occurs most often in the bones of the legs and pelvis in children and young adults under 20 years old. It is characterized by the genetic translocation t(11;22)(q24;q12) which fuses the EWS and FLI1 genes. Diagnosis involves patient history, physical exam, imaging tests like x-rays, CT, MRI and bone scans to identify tumors and metastases commonly in the lungs and bones. Pathological and molecular testing is also used to identify the genetic translocation.