Two days after removal of a large parathyroid adenoma in a patient whose preoperative calcium was 14 mg/dL with radiological osteitis fibrosa cystica, the patient develops tetany with calcium 5.8 mg/dL, phosphate 1.8 mg/dL, and marked hypomagnesaemia. Large volumes of intravenous calcium are required to maintain normocalcaemia. What is the diagnosis?

• A Permanent hypoparathyroidism from inadvertent total parathyroidectomy
• B Recurrent hyperparathyroidism from a missed second adenoma
• C Vitamin D deficiency unmasked after surgery
• D Hungry bone syndrome ✓

Explanation

Hungry bone syndrome is severe, prolonged hypocalcaemia, hypophosphataemia and hypomagnesaemia after curative parathyroidectomy in patients with high preoperative bone turnover. Demineralised bone avidly takes up calcium and phosphate once PTH falls. It differs from surgical hypoparathyroidism mainly by the hypophosphataemia, since hypoparathyroidism causes hyperphosphataemia, and it requires large quantities of calcium and magnesium replacement over days to weeks.

Reference: Schwartz's Principles of Surgery, 11th ed.

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Written and medically reviewed by the StethoPrep medical team.