Model released. Young child affected by Ewing's sarcoma of the leg playing in an hospital nursery. Ewing's sarcoma is a rare malignant form of bone cancer which mostly arises in large bones such as the femur, tibia, humerus and the pelvic bones; it spreads to other parts of the body at an early stage. The condition is most common in children between 10 and 15 years of age. The affected bone is painful, tender and may also become weakened and fracture easily. Treatment is with radiotherapy and chemotherapy with anticancer drugs. The blue device seen at right is used to control the infusion of the anticancer drugs.