<prompt> 76 year old man presents with lytic lesion in the vebrae. X-Ray skull showed multiple punched out lesions. The diagnosis isMetastasisMultiple myelomaOsteomalaciaHyperparathyroidism  <response>: B i.e. Multiple Myeloma Old age, male sex veebral involvement lytic lesion indicate towards diagnosis of Metastasis Multiple myeloma. But Absence of primary and characterestic multiple punched out lesions on X-Ray skull is diagnostic of Multiple myelomaQ. Osteomalacia: - Loosers zoned or PseudofractureQ Hallmark Mnemonic - Losse Pencilin Fish - Pencilling-in- of veebral bodies - Cod - fish marked biconvex veebraeQ Hyper parathyroidism : - Brown tumorQ Mnemonic - - Sub periosteal ErosionQ Brown Erosed Salt Basket - Salt Pepper or Pepper - Pot skullQ - Basket work appearanceQ of coex Renal Osteodystrophydt CRF: - It combines findings of ostemalacia, hyperparathyroidism and bone sclerosis - Osteomalacia lit Loosers zone - Hyper PTH 1t Subperiosteal Erosion of bone - Osteosclerosis Vt Rugger Jersey spineQ End plate sclerosis with alternating bands of radiolucency In children with CRF, the combination of rickets hyperparathyroidism leads to Rotting Fence Post appearance.Q Multiple Myeloma: Two cardinal features are: Generalized reduction of bone density Osteopenia Localized areas of radiolucency Punched outQRain drop lesionsQ in red marrow areas i.e. axial skeletal - spine skull. In multiple Myeloma lytic lesions of spine are usually associated with some collapse soft tissue extension i.e. paraveebral soft tissue shadows differentiation from Metastasis. Differentiation from inflamatory lesions can be made as the interveebral disc space aicular surfaces are not affected. 