Which among the following represents the MOST COMMON site of osteosarcoma?

Ans. A. Lower end of femurMost commonly metaphyses of long bones is involved in Osteosarcoma.Following are the most common sites of involvement:* Proximal tibia* Proximal humerus* Distal femur45% of all bone sarcomas are accounted as Osteosarcoma. It is a spindle cell neoplasm that leads to the production of bone or osteoid.X-Ray of affected bone shows moth-eaten appearance. X-ray also reveals a cuff of periosteal new bone formation and a spiculated periosteal reaction (sunburst appearance) at the margin of the soft tissue mass (referred to as Codman's triangle).The response to preoperative chemotherapy is the most important prognostic factor for long term survival. Preoperative chemotherapy followed by limb sparing surgery which is again followed by postoperative chemotherapy is considered to be the standard management therapy.