<prompt> Most common primary bone tumour in adult bone is: March 2011ChondrosarcomaOsteogenic sarcomaAdamantinomaEwings sarcoma  <response>: Ans. B: Osteogenic sarcoma Of the primary bone malignancies, multiple myeloma is the commonest Osteosarcoma is the second most common, and a highly malignant primary bone tumour Osteosarcoma: Metaphyseal MC site: Lower end of femur Sunburst appearance Codmans triangle Pa:ient may present with metastasis to lungs Treefment: Chemotherapy limb salvage surgery 