<prompt> Osteosarcoma can develop in:Osteoid osteomaOsteoblastomaPagets diseaseAll of the above  <response>: Ans: c Pagets disease Ref: Maheswari, 4th ed,p. 221Osteosarcoma can develop secondary to premalignant diseases of the bone.They are usually less malignant seen in the older age group.Premalignant lesions are: Pagets disease Diaphyseal aclasis Enchondromatosis Post radiation 