High Grade Osteosarcomas

摘要: The osteosarcoma is a high-grade malignant tumor composed of mesenchymal cells producing osteoid and immature bone. This osteoblastic differentiation usually extensive prominent, but it can be only focal or minimal. Hence, the should not confused with fibrosarcoma (when extensively spindle cellular collageno-genic), fibrous histiocytoma includes histio-fibroblastic areas storiform pattern), chondrosarcoma also produces cartilage), an aneurysmal bone cyst telangiectatic containing osteoclast like giant cells), Ewing’s sarcoma small cells). almost constantly intramedullary tumor, in rare cases may originate at surface bone, exceptionally develops intracortically. Osteosarcomas occasionally have skip more distant skeletal metastases, they multifocal skeleton from start.