A 68-year-old man presents with progressive bowing of the right tibia, skull enlargement requiring larger hat size, and bilateral sensorineural hearing loss. Serum alkaline phosphatase is markedly elevated with normal calcium and phosphate. The diagnosis is:
- A Paget's disease of bone ✓
- B Hyperparathyroidism
- C Osteomalacia
- D Fibrous dysplasia
Correct answer: A. Paget's disease of bone
Explanation
Paget's disease of bone is a chronic metabolic disorder of markedly elevated and disorganised bone remodelling, causing bone enlargement, deformity, and pain. The classic triad includes enlarged skull (frontal bossing), bowing of long bones especially the tibia ('sabre tibia'), and deafness from involvement of the bony labyrinth and cochlea. Alkaline phosphatase is a marker of osteoblast activity and is the highest in Paget's among metabolic bone diseases. Treatment is with bisphosphonates.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.