摘要: The definition of osteosarcoma requires that a malignant tumor bone produce osteoid or bony matrix. With this as basic definition, can be divided into several clinicopathologic entities based on clinical, roentgenographic, and pathologic features. tumors broadly those arising within the surface bone. Most intraosseous osteosarcomas are high-grade occur in children adolescents. A small number older patients, they may related to preexisting condition, such Paget's disease radiation. site lesion has prognostic importance. Osteosarcoma jaws is associated with an especially good prognosis, whereas same kind involving skull very poor prognosis. well moderately differentiated excellent