<prompt> Commonest malignant tumor of skeletal system ?Multiple myelomaMetastasisOsteosarcomaChondrosarcoma  <response>: Ans. is b i.e., Metastasis Commonest bone malignancies -Secondaries Commonest primary malignant tumor - A- Multiple myeloma Commonest primary malignant tumor - Osteosarcoma of long bones Commonest benign tumor of bone - - Osteochondroma Osteochondroma is not true neoplasm since its growth stops with cessation of growth at the epiphyseal plate Commonest true benign tumor of bone - Osteoid osteoma Commonest benign tumor of hand - Enchondroma 