40 yrs (middle aged old) - Metastasis (breast, lung), prostate, renal, thyroid, colon- Multiple myeloma- Lymphoma- Paget's disease- Hyperpara thyroidism- OsteomyelitisEnchondroma15-40 Osteoclastoma (GCC)20-40q ChondrosarcomaFibrosarcoma30-60q Lymphoma Multiple myelomaMetastasis>50q">