True regarding osteosarcoma is-

Ans. is 'b' i.e Sunray appearance in X-ray indicates new bone formation Osteosarcoma occurs because of proliferation of osteoblasts* (not osteoclasts)Age groupPrimary osteosarcoma - 15-25yrsSecondary osteosarcoma - older age, >45yrsAs with any other sarcoma it spreads through blood stream and does not metastasize to lymphatics.Sun ray appearance on X-ray :As the periosteum is unable to contain the tumor, the tumor grows into the overlying soft tissues. New bone is laid down along the blood vessels within the tumor growing centrifugally giving rise to sunray appearance on the X-ray.Children with retinoblastoma* have an increased incidence of osteosarcoma.