الفهرس 
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Abstract
Osteosarcoma is the most common bone sarcoma and the third most common malignancy in children and adolescents. The Annual incidence of osteosarcoma is about 400-1000 new cases diagnosed per year in the United States, giving osteosarcoma an incidence of about 3/1,000,000 population. It is largely a disease of youth, with more than 75% of cases occurring in those less than 25 years of age. Osteosarcomas are slightly more common in males than females, with an exception to this tendency is paraosteal osteosarcoma, which is more common in females and occurs in a slightly older age group. Although osteosarcoma can occur in any bone, The most frequent sites of origin are the metaphyseal regions of the distal femur, proximal tibia and proximal humerus.
Most osteosarcomas are de novo tumours of unknown aetiology, secondary causes include ionising radiation, hereditary retinoblastoma, Paget’s disease of bone, enchondromatosis, hereditary multiple exostoses and fibrous dysplasia.
Patients present with severe pain of relatively short duration, often with a firm to hard mass, stretched, shiny overlying skin, and prominent vascular markings.