Bone Tumors: Primary Bone Cancers.

The three most common primary bone cancers are osteosarcoma, Ewing sarcoma, and chondrosarcoma. Osteosarcoma occurs most often in children and young adults, with a peak incidence at ages 10 to 14 years. It also can occur later in life due to malignant transformation of benign bone lesions. Osteosarcoma occurs most commonly around the knee, but can occur in other bones. Management varies depending on tumor characteristics and involves chemotherapy and surgery. Ewing sarcoma is most common in teenagers. It occurs most commonly in long bones but can occur in the pelvis and other bones. Management involves surgical resection when possible, along with chemotherapy and occasionally radiation therapy. Chondrosarcoma typically occurs in patients 40 years and older. It can occur as a primary tumor or from malignant transformation of benign bone tumors. Chondrosarcomas are relatively resistant to chemoradiation, so surgery is the standard therapy. When any of these tumors is suspected, patients should be instructed to avoid weight-bearing on the affected extremity to help prevent pathologic fracture while evaluation is completed. Imaging with x-rays and occasionally magnetic resonance imaging study are the initial diagnostic steps. If imaging suggests a primary bone cancer, prompt referral to an orthopedic oncology subspecialist is indicated.