Endocrine Abstracts

Introduction: Immobilization hypercalcemia (IH) is more common in children and adolescent due to increased rate of bone turnover and it usually develop 4–6 weeks post trauma but it can begin as early as 2 weeks and as late as six months. We report a patient who developed severer hypercalcemia after sustaining multiple fractures and immobilization.

Case

A 24-year-old man was admitted for neurorehabilitation after road traffic accident, sustaining a subarachanoid haemorrhage and multiple fractures. Four months after admission, he developed severe hypercalcemia of (3.63 mmol/l) and PTH was suppressed at 0.9 pmol/l. He had mild renal impairment initially. Thyroid and adrenal function, serum ACE, vitamin D and PTHrp were normal. Serum protein electrophoresis and skeletal survey was normal which excluded multiple myeloma. CT Thorax, abdomen and pelvis and bone scan were unremarkable except hypertrophic calcification around the hips. Normocalcaemia was achieved following intravenous fluids and zoledronic acid. After extensive investigation a diagnosis of immobilization hypercalcemia (IH) was made. Serum calcium was normal when last checked nine weeks after bisphosphonate therapy.

Discussion: Immobilization hypercalcemia (IH) is an under-recognized cause of hypercalcaemia. Risk factors include more severe immobilisation, pre-existing renal disease, and childhood/adolescence. Although our patient presented later after his trauma than average, the diagnosis should be considered in appropriate clinical setting after excluding other common causes of hypercalcaemia. Clinical suspicion of IH may reduce the need for unnecessary invasive procedures.