Osteosarcoma: Symptoms, Diagnosis, Treatment, Prognosis Introduction of Osteosarcoma Osteosarcoma is a highly malignant tumour arising within the bone and spreading rapidly outwards to the periosteum and surrounding soft tissues. It is said to occur predominantly in children and adolescents, but epidemiological studies suggest that between 1972 and 1981 the age of … [Read more...] about Osteosarcoma: Symptoms, Diagnosis, Treatment, Prognosis