Patients will be enrolled in the study if they have a lytic lesion of the humerus, femur, or tibia which satisfies at least one of the following criteria: the lesion encompasses at least 50% of the width of the bone at that point on both AP and lateral radiographs; the lesion has caused a change in the anatomical shape and contour of the bone; the lesion has a bone density less than 50% of the density of the contralateral, normal side.