A 42-year-old woman undergoes removal of a 4 cm parathyroid adenoma. Preoperatively her calcium was 14.5 mg/dL with radiological evidence of osteitis fibrosa cystica and a raised alkaline phosphatase. On postoperative day 3 her calcium is 5.8 mg/dL with phosphate 2.0 mg/dL and magnesium normal. Intravenous calcium infusion produces only transient correction. What is the diagnosis?

• A Hungry bone syndrome ✓
• B Permanent hypoparathyroidism from accidental excision of all four glands
• C Hypomagnesaemia-related functional hypoparathyroidism
• D Recurrent laryngeal nerve injury causing hyperventilation and respiratory alkalosis

Explanation

Hungry bone syndrome is profound, prolonged hypocalcaemia after parathyroidectomy in patients with severe, long-standing primary hyperparathyroidism and high preoperative bone turnover, indicated here by osteitis fibrosa cystica and raised alkaline phosphatase. Rapid remineralisation of the skeleton sequesters calcium and phosphate, so hypophosphataemia is typical, unlike hypoparathyroidism where phosphate is high. Management needs aggressive calcium with active vitamin D and often prolonged infusion. Normal magnesium excludes functional hypoparathyroidism from magnesium deficiency.

Reference: Williams Textbook of Endocrinology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.