Three days after total parathyroidectomy for severe primary hyperparathyroidism, a patient develops carpopedal spasm, perioral tingling, a positive Chvostek sign, and a corrected serum calcium of 6.8 mg/dL. Serum phosphate is elevated and magnesium is normal. What is the most likely explanation?
- A Recurrent laryngeal nerve injury causing hyperventilation
- B Permanent surgical hypoparathyroidism alone, unrelated to bone turnover
- C Hungry bone syndrome due to rapid mineral deposition into previously resorbed skeleton ✓
- D Magnesium deficiency impairing parathyroid hormone secretion
Correct answer: C. Hungry bone syndrome due to rapid mineral deposition into previously resorbed skeleton
Explanation
Hungry bone syndrome occurs after removal of chronically overactive parathyroid tissue, particularly when preoperative alkaline phosphatase and PTH were markedly elevated. The unmasked skeleton avidly takes up calcium and phosphate, producing abrupt hypocalcaemia, hyperphosphataemia and tetany within days of surgery. Pure surgical hypoparathyroidism causes low phosphate because PTH normally promotes phosphaturia, so the combination of hypocalcaemia with high phosphate points to skeletal uptake rather than option B. Normal magnesium excludes option D.
Reference: Bailey and Love's Short Practice of Surgery, 28th ed.
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Written and medically reviewed by the StethoPrep medical team.