Endocrine Abstracts

Background: Hungry Bone Syndrome (HBS) is a rare but serious complication following parathyroidectomy for primary hyperparathyroidism (PHPT), particularly in patients with long-standing disease and significant skeletal involvement. This case highlights the clinical challenges in managing advanced PHPT complicated by obstructive nephrolithiasis and the postoperative metabolic derangements of HBS.

Case Presentation: A 27-year-old male with a history of acute pancreatitis and prior appendectomy presented to the Emergency Department with fever, right flank pain, and visible hematuria. Imaging revealed a 4×3 mm obstructing right proximal ureteric stone with hydronephrosis. Biochemical evaluation showed severe hypercalcemia (adjusted calcium 3.14 mmol/l), elevated PTH (48.85 pmol/l), low vitamin D (17 nmol/l), and high ALP (367 U/l), suggestive of metabolic bone disease secondary to PHPT. The patient had been diagnosed with PHPT abroad and was awaiting specialist review in the UK. He underwent urological management with stenting and nephrostomy due to recurrent obstruction. Parathyroid imaging revealed a large left inferior parathyroid adenoma (3.1 × 2.2 cm) confirmed on SPECT-CT. Two months post initial presentation, he underwent successful parathyroidectomy. Two days postoperatively, he developed symptomatic hypocalcemia, with a normal adjusted calcium of 2.17 mmol/l, persistent elevation in ALP, and a transiently suppressed PTH (1.07 pmol/l), with low vitamin D (21) consistent with Hungry Bone Syndrome. He was commenced on Colecalciferol, with repeat calcium check after 24 hours indicating this was starting to increase and PTH later normalized to 7.52 pmol/l.

Conclusion: This case illustrates the importance of early recognition and multidisciplinary management of PHPT, particularly in younger patients presenting with renal complications. Timely parathyroidectomy is essential to prevent end-organ damage. Postoperative monitoring for HBS is critical, especially in patients with severe bone disease, high ALP, and vitamin D deficiency pre-operatively.