<prompt> A 58 years old woman, who had backache and recurrent chest infections for 6 months, develops sudden weakness of the legs and urinary retention. Her investigations show hemoglobin of 7.3 gmd1, serum calcium 12.6 mgd1, phosphate 2.5 mgdl, alkaline phosphatse 100 uil, serum albumin 3 gmd1, globulin 7.1 gmd1, and urea 178 mgdl. What is the most likely diagnosis ?Lung cancerDisseminated tuberculosisMultiple myelomaOsteoporosis  <response>: Answer is C Multiple myeloma Backache and Recurrent infections in the backdrop of normal alkaline phosphatase levels and a reversed albumin globulin ratio A : G ratio is highly suggestive of the diagnosis of multiple myeloma. Interpretation of information provided in the question Clinical information Laboratory parameters Infomation Interpretation Parameter Normal Patients Interpretation Backache Bony pains Haemoglobin 12 - 16gm 7.3 Anemia Weakness of legs Cord Serum Ca- 9.0 - 10.5mgd1 12.6 Hypercalcemia urinary retention compression Alkaline phosphatase 30-120 UI 100 Normal Chest infection Ineffective Albumin 3.5 - 5.5 gmdl 3.0 Normal recurrent defence against Globulin 2.0 - 3.5 gmdi 7.1 Elevated infection Urea 20 - 40 mgdl 178 Elevated Both clinical findings and laboratory data suggest the diagnosis of Multiple Myeloma Serum Alkaline Phosphatase is usually normal even with extensive bone involvement.-- Harrison Serum Albumin is normal or low, Total protein is normal or raised.-- Kumar 5th501 