Bone Marrow Sarcoidosis: Hiding Within an Evaluation of Hypercalcemia

Patients with granulomatous disease often have widespread pulmonary and extrapulmonary disease. In the absence of this, a search of the pulmonary, renal, hepatic, ocular, and bone marrow is warranted in the setting of hypercalcemia with unexplained elevated 1,25-dihydroxyvitamin D, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). We present a case of hypercalcemia and a decline in renal function in a patient with bone marrow sarcoidosis. A 45-year-old woman was admitted to the hospital after hypercalcemia, acute kidney injury, and pancytopenia were found on a routine outpatient lab. She was discharged after improvement with IV fluids. She had interval worsening of hypercalcemia and was readmitted within a week for pamidronate treatment. Imaging and labs were concerning for sarcoidosis, but bronchoscopy with biopsy was nondiagnostic. Eventual bone marrow biopsy confirmed evidence of granulomas. Her condition improved with prednisone over 3 months and ultimately, azathioprine. Non-parathyroid hormone-mediated hypercalcemia should be thoroughly worked up for a source to rule out malignancy and to diagnose treatable causes such as sarcoidosis. Sarcoidosis may not present in its traditional pulmonary pattern, necessitating further diagnostic measures such as a bone marrow biopsy.