A 68-year-old man presents with bowing of the right tibia, right tibial pain, and a raised alkaline phosphatase (ALP) of 620 IU/L with normal serum calcium and phosphate. Skull X-ray shows 'cotton wool' appearance. A bone scan shows intense uptake in the right tibia and skull. The complication of Paget's disease that occurs in this bone over 1% of cases is:
- A Osteoporotic fracture through pagetic bone
- B Secondary hyperparathyroidism from calcium depletion
- C Sarcomatous change (Paget's sarcoma — osteosarcoma) in pagetic bone ✓
- D Infection of pagetic bone (pagetic osteomyelitis)
Explanation
Malignant transformation of Paget's disease to sarcoma (typically osteosarcoma, occasionally fibrosarcoma or MFH) occurs in approximately 1% of patients with polyostotic Paget's disease — the most feared complication. It typically presents as sudden intensification of pain in pagetic bone, a new soft tissue mass, or rising ALP above established levels. Prognosis is extremely poor (median survival <1 year). Pagetic sarcoma arises in older patients (70s–80s) and is most common in the femur, humerus, and pelvis. Fractures through pagetic bone (banana fractures, chalk-stick fractures) are common but benign complications. Secondary hyperparathyroidism is not a feature of Paget's.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.