Introduction: Osteosarcoma usually originates in the metaphyseal region of long bone, but may also arise in the diaphyseal of long bone. Diaphyseal osteosarcoma is a rare cases account for <10% of all osteosarcoma. In some cases two or more osteosarcoma lesions are seen in the same patient, at the same time (Synchronous osteosarcoma). It’s unusual condition of osteosarcoma, they are found at a frequency of about 1–3% osteosarcoma cases.