A 68-year-old man presents with increasing hat size, hearing loss, and bone pain. Serum alkaline phosphatase is markedly elevated. Bone scan shows intense uptake in the skull, pelvis, and right femur. The complication most feared in Paget's disease of bone involving a long bone is:
- A Pathological fracture through pagetic bone
- B Hypercalcemia requiring emergency dialysis
- C Malignant transformation to osteosarcoma (sarcomatous degeneration) ✓
- D Avascular necrosis of the femoral head
Explanation
Malignant sarcomatous transformation (most commonly osteosarcoma, rarely fibrosarcoma or chondrosarcoma) is the most feared complication of Paget's disease, occurring in <1% of cases but carrying an extremely poor prognosis with 5-year survival <10%. It should be suspected when a patient with known Paget's develops sudden increase in pain, rapid swelling, or marked rise in ALP. Pathological fractures (banana/fissure fractures on the convex cortex) are more common but are not 'most feared' due to relatively manageable treatment. Hypercalcemia occurs only with immobilization in polyostotic disease, not routinely.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.