<prompt> Commonest malignant tumor of skeletal system -Multiple myelomaMetastasisOsteosarcomaChondrosarcoma  <response>: Ans. is b i.e., MetastasisImportant factso Commonest bone malignancies-Secondarieso Commonest primary malignant tumor-Multiple myelomao Commonest primary malignant tumor of long bones-Osteosarcomao Commonest benign tumor of boneOsteochondroma is not true neoplasm since its growth stops with cessation of growth at the epiphyseal plate-Osteochondromao Commonest true benign tumor of bone-Osteoid osteomao Commonest benign tumor of hand-Enchondroma 