Ewing Sarcoma

Ewing sarcoma is a type of pediatric cancer that forms in bone or soft tissue, representing about 2 percent of childhood cancers and affecting roughly one in a million people annually in the United States. Its cause is unknown and most cases appear to occur randomly, though about 85 percent involve a specific genetic event, a reciprocal translocation between chromosomes 11 and 22 that fuses the EWSR1 and FLI1 genes. Symptoms include swelling and pain at the tumor site, fever, and bone fracture, and it most commonly develops in the legs, pelvis, and chest wall of teenagers and young adults, with a peak age around 19.