SAT-491 Severe Hypercalcemia Secondary to Primary Skeletal Sarcoidosis

Introduction: Sarcoidosis is an autoimmune disorder that is characterized by non-caseating granulomas found throughout affected tissues. It has an incidence of 10-12 per 100,000 patients per year (2). Common clinical manifestations of sarcoidosis include hilar adenopathy, abnormally high angiotensin-converting enzyme (ACE), abnormally high vitamin D, and respiratory symptoms such as cough. While the lungs are commonly affected by sarcoidosis, extrapulmonary involvement occurs in over 30% of cases of sarcoidosis (1). The incidence of musculoskeletal involvement, specifically, is approximately 14%, however, most cases are asymptomatic (2). Case Presentation: A 79-year-old female with a past medical history of asthma, dementia, CAD, CKD, and HTN presents with asymptomatic hypercalcemia. She was directly admitted for hypercalcemia, AKI, and UTI and was started on Keflex and IV fluid therapy. Endocrinology, rheumatology, oncology, and nephrology were consulted. Over the course of her evaluation, further labs revealed: continued hypercalcemia: with a nadir of 13.5, elevated 1,25 vitamin D with a nadir of 100.0, and elevated ACE levels with a nadir of 125. Phosphorus, magnesium, PTH, and PTHrP levels were all within normal limits. The patient’s only complaint was dry mouth. Repeat physical examinations were stable and within normal limits other than increasing blood pressure, as high 172/70. She was started on dexamethasone to decrease conversion of Vitamin D to 1,25 hydroxyvitamin D. Throughout her stay, the patient had a negative NM parathyroid scan and a negative full body PET-CT. A CT chest w/o contrast revealed nonsp ecific ground-glass opacification with interval resolution of a small pulmonary nodule. Her diagnosis of sarcoidosis was only confirmed with a bone marrow biopsy of her right posterior iliac crest that revealed multiple non-necrotizing granulomas. Discussion: Atypical presentations of illnesses warrant exhaustive diagnostic workup. Although this patient’s laboratory values classically pointed towards a granulomatous process - elevated vitamin D and ACE levels - her diagnostic imaging studies, including full body PET-CT, were negative, steering away from a diagnosis of skeletal sarcoidosis. If it were not for a bone marrow biopsy, this patient would have potentially suffered greatly with the development of cystic bony degeneration and consequences such as fracture needing invasive orthopedic surgical intervention.