Endocrine Abstracts

Sarcoidosis is rare cause for hypercalcaemia, where PTH is suppressed. Primary Hyperparathyroidism is a common disorder where high Parathyroid Hormone (PTH) causes hypercalcaemia leading to renal and skeletal complications. We describe a patient where PTH hypersecretion worsened hypercalcaemia from sarcoidosis. A 69-year-old gentleman on long -term Prednisolone (10-20 mg/d) for sarcoidosis with lung nodules and mediastinal lymphadenopathy had moderate hypercalcaemia of 2.4-2.6 mmol/L (2.1-2.55) for around ten years but presented acutely with symptomatic increase in corrected calcium to 3.07 mmol/L (2.1- 2.55), normal phosphate 1.0 mmol/L (0.8-1.5), high PTH 19.3 pmol/l (1.6-7.2). He had mild chronic kidney disease with serum creatinine of 119 umol/L (63-111), and vitamin D 93 nmol/l (50-150). He was diagnosed with primary hyperparathyroidism, but parathyroid adenoma was not identified on ultrasound or sestamibi scans. After neck exploration three normal parathyroid glands were removed. The left inferior parathyroid was not found. Although left thyroid lobectomy was performed for suspected intrathyroidal parathyroid adenoma, this was ruled out on histology. Post operative calcium remained mildly high (2.5 – 2.65 mmol/l), although PTH level normalised (6.5 pmol/l). Post operatively low dose steroids was continued for sarcoidosis. As steroids were weaned, he presented again with hypertensive seizures and confusion. His corrected calcium was 3.44 mmol/L with suppressed PTH of 2.9 pmol/l. His creatinine was 186 umol/L and vitamin D 82.8 nmol/l. He was diagnosed with Posterior Reversible Encephalopathy Syndrome and treated with antihypertensives, intravenous fluids, and bisphosphonate infusion. Prednisolone (10 – 20 mg/d) was restarted for progression of lung nodules and rising serum ACE levels. He remains clinically stable with calcium in reference range on Prednisolone. Our case demonstrates diagnostic and management conundrum when high calcium is from co-existence of PTH-dependent and PTH-independent causes in the same patient.