An osteosarcoma is a cancerous tumor in a bone. Specifically, it is an aggressive malignant neoplasm that arises from primitive transformed cells of mesenchymal origin (and thus a sarcoma) and that exhibits osteoblastic differentiation and produces malignant osteoid. The most common sites include the femur (42%), with 75% of tumors in the distal femur; tibia (19%), with 80% of tumors in the proximal tibia; and humerus (10%), with 90% of tumors in the proximal humerus. Other locations of note include the skull or jaw (8%) and pelvis (8%).
In Argentina, the incidence of osteosarcoma is slightly higher in males than in females. In males, it is 5.2 per million per year; in females, it is 4.5 per million per year. A complete radical, surgical, en bloc resection of the cancer, is the treatment of choice in osteosarcoma. Although about 90% of patients are able to have limb-salvage surgery, complications, particularly infection, prosthetic loosening and non-union, or local tumor recurrence may cause the need for further surgery or amputation.