An x-ray showing an osteosarcoma in the humerus. Photograph: Connectedkansaskids.com
"Osteosarcoma" - a cancerous tumour of the bone that spreads rapidly to the lungs and, less commonly, to other areas. An osteosarcoma may occur in adolescents for no known reason (usually in a long bone of the arm or leg or around the knee, hip, or shoulder). In elderly people, osteosarcomas may develop in several bones as a late, rare complication of Paget's disease. The tumour causes pain, swelling of the affected bone if it occurs near the surface.
The condition may be treated by radiotherapy, but the affected bone is usually surgically removed. Sometimes it is replaced by a bone graft or artificial bone, but most often, an amputation and a prosthesis (artificial limb) are required. Anti-cancer drugs improve the outlook; about half of those in whom the disease is discovered early are cured.
"osteosarcoma". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p424.