Commonest bone malignancy is:

Ans: D (Secondaries) "Metastatic deposits in the bone are commoner than primary tumor. Of the primary bone malignancies, multiple myeloma is the commonest. Osteochondroma is the commonest benign tumor"- Maheswari 3rd/214METASTATIC BONE TUMORSCarcinomas often metastasize to the skeleton, and metastatic lesions are much more common than primary' bone lesions in general orthopaedic practice.The five primary cancers with a strong propensity to metastasize to bone are those originating in the breast, prostate, lung., kidney, and thyroid.The axial skeleton^, including the skull, thoracic spine, ribs, lumbar spine, and pelvis, is most commonly involved. The proximal long bones, particularly the humerus and femur, also are affected frequently. Acral (distal) metastases are uncommon0 and are almost always secondary to lung carcinoma when they do occur.The predilection of particular tumors for bone, and forparticular regions of specific bones, is thought to be caused by cytokines, local growth factors, or matrix components that attract and support growth of these lesions in spedfic areas. Lesions can be blastic (breast, prostate), lytic (breast, lung, myeloma, kidney, thyroid), or mixed (breast, lung) in radiographic appearance. Blastic or sclerotic lesions are less prone to pathologic fractures. Age predilection || |TumorAge range (yrs) AgeBenignMalignantOther 0-5 yrs (child)- Eosinophilic granuloma- Unicameral bone cyst (rare)- Leukemia- Metastatic neuroblastoma- Osteomyelitis- Stress fractureEosinophilic granuloma Ewing's tumor1-155-15 6-18 yrs(youngadolescent)- Unicameral bone cyst- Aneurysmal bone cyst- Eosinophilic granuloma- Enchondroma- Chondroblastoma- Chondromyxoid fibroma- Ewing's sarcoma- Osteo sarcoma Non ossifying fibroma Fibrous cortical defect Simple (unicameral) bone cyst2-20 Aneurysmal hone cyst5-20 Osteogenic sarcoma5-20 Chondroblastoma Chondromyxoid fibroma5-2510-30 19-40 yrs (adult)- Osteoblastoma- Osteoclastoma- Eosnophilie granuloma- Ewing's sarcoma Osteoid osteoma Osteoblastoma10-35 > 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