Ewing sarcoma is the second most common tumor of the bone. It most often affects bones of the pelvis, the tibia, fibula, and femur, and can also begin in the soft tissues. This disease most often occurs in adolescents, with nearly half of cases arising between the ages of 10 and 20.
The cause of Ewing sarcoma in children is still unknown. It is not typically associated with any other cancer syndromes. Additionally, there is no additional risk among families in which a single person has Ewing sarcoma.