Endocrine Abstracts

Introduction: Hypercalcaemic crisis (adjusted calcium>3.5 mmol/l) is a medical emergency requiring urgent treatment. This is usually associated with malignancy, but here, we present a case of a young woman admitted with hypercalcaemic crisis and multisystem involvement.

Case Presentation: A 28-year-old Caucasian woman with no medical history presented to emergency department with a 4-month history of weight loss (7 kg), abdominal pain, anorexia, recurrent vomiting, and amenorrhoea. On initial investigations, she was found to have severe hypercalcaemia (adjusted calcium 4.06 mmol/l) and severe acute kidney injury (serum creatinine 197 µmol/l, eGFR 29ml/min/1.73m2), with profound microcytic anaemia (Hb 56 g/l). An urgent computerized tomography (CT) scan demonstrated massive splenomegaly, hepatomegaly with multiple para-aortic, portal and peri-splenic lymph nodes. Further investigations revealed low parathyroid hormone (PTH) levels (0.7 pmol/l), and an oesophago-gastro-duodenoscopy (OGD) was normal except a small anterior stomach wall lesion, which was biopsied with normal pathology. On examination, she appeared very tanned, and further questioning revealed that her symptoms began after two back-to-back holidays along the Mediterranean coast with substantial sun exposure. Serum cortisol levels were 528 nmol/l ruling out adrenal insufficiency, and 1,25(OH) vitamin D levels were very high (261pmol/l; normal=43-144), suggesting extra-renal vitamin D conversion. Serum angiotensin converting enzyme (ACE) levels were markedly elevated (>150 IU/l; normal=20-70). Hypercalcaemia was conservatively managed with intravenous fluids initially, with partial success. Supraclavicular lymph node biopsy revealed non-caseating granulomatous lymphadenitis, confirming sarcoidosis. The patient was subsequently started on glucocorticoids with rapid normalization of symptoms and calcium levels.

Conclusions: 1. Detailed history in this case established the link between sun exposure and onset of symptoms. 2. Sun exposure in granulomatous disorders results in extra-renal conversion of 25(OH) vitamin D to activated 1,25(OH) vitamin D via 1-alpha-hydroxylase enzyme in the macrophages, resulting in hypercalcaemia.