<prompt> True about bone tumor is:Multiple myeloma is seen in more than 55 years age and aboveOsteogenic sarcoma-fouh decadeChondrosarcoma -first decadeOsteoclastoma- fifth decade  <response>: AGE Tumors 1st Decade Ewings sarcoma Can be 5-20 years, Unicameral Bone Cyst Retinoblastoma Rhabdomyosarcoma Metastasis from Neuroblastoma 2nd Decade Osteosarcoma Can affect all ages Aneurysmal Bone Cyst Giant cell tumor 20-40 years-classical is 30 years Adamantinoma Enchondroma After 40Yrs Multiple myeloma Chondrosarcoma. Note: Ewings sarcoma is commonest bone tumor of 1st decade but its peak incidence is 2nd decade. 