A 50-year-old man has pain in the back and multiple osteolytic lesions of the skull, spine, and ribs. Serum calcium is 12.5 mg/dL, serum protein is elevated, and urine shows Bence Jones proteins. The most likely diagnosis is:
- A Metastatic carcinoma from prostate
- B Multiple myeloma ✓
- C Hyperparathyroidism with brown tumours
- D Lymphoma of bone
Correct answer: B. Multiple myeloma
Explanation
Multiple myeloma is the most common primary malignant tumour of bone in adults over 40, arising from plasma cells of the bone marrow. It produces multiple punched-out osteolytic lesions (raindrop skull on X-ray), hypercalcaemia, anaemia, renal impairment, and elevated total protein with a monoclonal spike on electrophoresis. Bence Jones proteins (immunoglobulin light chains) are pathognomonic in urine. Bone scans are often falsely negative because purely lytic lesions lack new bone formation.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.