ODP645 A Rare Case of Extrapulmonary Sarcoidosis with Hypercalcemia as the Initial Presentation: A Diagnostic Conundrum
Authors: Saeed Zainab , Abdelmasih Randa , Ashraf Bilal , Labib Christine , Ramharrack Frank 
Published: November 2022

Abstract

Introduction
Sarcoidosis is a multi-system chronic granulomatous disease of unknown etiology with a wide array of manifestations. It most commonly affects the lungs. About 30% of the patients present with extra pulmonary sarcoidosis along with lung involvement and approximately 8% present with disease at extrapulmonary site without lung involvement. Here we present a case of asymptomatic extrapulmonary sarcoidosis that presented with hypercalcemia, later confirmed with an axillary node biopsy showing non-caseating granuloma.

Case Presentation
A 56-year-old male with a past medical history of renal insufficiency presented with an elevated Calcium (Ca) of 11mg/dL, asymptomatic otherwise. Further lab testing revealed a suppressed Parathyroid hormone (PTH) level of 2 pg/ml, Parathyroid hormone related protein (PTHrP) of 14pmol/L, normal 25-Hydroxy Vitamin D (27ng/ml), markedly elevated calcitriol (106 pg/ml) and 24-hour urinary Calcium (961mg/day). Patient also had renal insufficiency with a creatinine of 1.58mg/dL and glomerular filtration rate of 49ml/min/1.73m2. Angiotensin-converting enzyme (ACE) was also found to b elevated at 125units/L. Computed Tomography (CT)) chest showed scattered pulmonary nodules measuring as large as 7.9 mm, CT scan of abdomen revealed splenomegaly and bilateral non-obstructing renal calculi. A subsequent NM bone scan and X-ray bone survey were unremarkable. Patient's calcium levels progressively increased to a maximum of 13.3. A flow cytometry showed no immunophenotypic evidence of a lymphoproliferative disorder. Due to concern for malignancy, a PET scan was done which revealed small scattered hypermetabolic lymph nodes in bilateral external iliac chain and upper retroperitoneum. A solitary hypermetabolic 10mm right axillary lymph node was seen which was then biopsied. Biopsy report showed epitheloid non-necrotizing granuloma and fibrosis, thus confirming diagnosis of sarcoidosis. Patient was started on prednisone 10mg daily empirically before the biopsy results and repeat calcium in 2 months came back at 9.6mg/dl. He was then switched to a maintenance dose of 5 mg.

Case Discussion
Hypercalcemia is a common clinical laboratory abnormality with 90% of cases attributed to PTH-dependent hyperparathyroidism and malignancy. Although rare, chronic granulomatous diseases can cause a PTH-independent hypercalcemia through enhanced conversion of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D. Sarcoidosis makes up only 1% of cases of hypercalcemia, making it very challenging to diagnose it as an etiology of hypercalcemia. Furthermore, hypercalcemia is rarely the initial presentation as it happened in our case. All cases of hypercalcemia must be thoroughly evaluated with PTH, 1,25-hydroxyvitamin D, and PTHrP to rule out common etiologies. Corticosteroids are the main stay of treatment of hypercalcemia in sarcoidosis. This case aims to shed light on sarcoidosis as an etiology of hypercalcemia, even though rare, for prompt diagnosis and management.
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