A 50-year-old man with chronic kidney disease on hemodialysis for 8 years presents with diffuse bone pain, proximal myopathy, and pruritus. Lab shows calcium 8.1 mg/dL, phosphate 6.8 mg/dL, PTH 900 pg/mL, and elevated alkaline phosphatase. X-ray reveals subperiosteal resorption of the radial aspect of the middle phalanges and a 'rugger jersey' spine. The diagnosis is:
- A Secondary hyperparathyroidism (renal osteodystrophy) ✓
- B Primary hyperparathyroidism
- C Tertiary hyperparathyroidism
- D Tumor-induced osteomalacia
Correct answer: A. Secondary hyperparathyroidism (renal osteodystrophy)
Explanation
CKD causes phosphate retention and impaired 1-alpha hydroxylation, driving secondary hyperparathyroidism. Subperiosteal resorption at radial phalanges and 'rugger jersey' spine (sclerotic bands adjacent to endplates) are classic. Tertiary hyperparathyroidism occurs post-transplant with autonomous PTH secretion despite corrected renal function. Primary hyperparathyroidism would show hypercalcemia, not this CKD picture.
Reference: Harrison's Principles of Internal Medicine, 20th ed.
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Written and medically reviewed by the StethoPrep medical team.