Osteosarcoma occurs mainly in the metaphysic of the long bones. Most tumors arise in bones involved with the knee joint at the distal end of the femur or proximal distal end of the tibia. As a tumor of the mesenchymal cells, osteosarcoma demonstrates production of osteiod tissue. The tumor borders are distinct and merge into adjacent normal bone.
Osteosarcoma tends to occur in children and young adults, but it can also occur in older adults. Osteosarcoma treatment often involves surgery, chemotherapy and radiation therapy. The National Cancer Institute and is designated as a comprehensive cancer center — recognition for an institution's scientific excellence and multidisciplinary resources focused on cancer prevention, diagnosis and treatment.