Sarcoidosis Found in the Bone Marrow

Introduction: 90% of patients who present with hypercalcemia are likely due to primary hyperparathyroidism or malignancy, with the alternative diagnosis of sarcoidosis. Sarcoidosis tends to affect the lung in 95% of cases and about 4% of cases affect the bone marrow. Patients tend to present with vague symptoms of faigue, shortness of breath, arthralgias, and fevers. We present a case of a patient who presented with hypercalcemia and the work-up that it entailed. Case Description: Patient is a 69-year-old woman with a history of hypertension, microcytic anemia, atrial fibrillation, chronic kidney disease stage 4, proteinuria, and insulin dependent diabetes mellitus type 2 who presented to the Nephrology clinic due to acute renal failure which was presumed due to acute tubular necrosis and overdiuresis. Patient was undergoing work up with Hematology due to microcytic anemia and was noted to have hypercalcemia. There was concern for multiple myeloma, so extensive work up consisted of negative Serum protein electrophoresis, flow cytometry, and kappa/lambda . Bone marrow biopsy was obtained for further clarification and was found to have granulomas in the bone marrow (Fig. 1). Extensive infectious work up performed including fungal etiologies which was negative. The angiotensin converting enzyme was elevated at 178 U/L. Kidney involvement was highly suspected due to intrinsic pathology consistent with urinalysis. She started on prednisone and her kidney function has normalized, her calcium as well as her angiotensin converting enzyme level is normal currently and prednisone is being weaned. Her fatigue and tiredness have resolved. Discussion: Sarcoidosis presenting only with bone marrow granulomas and no lung finding is a very rare presentation. Our patient did not have any joint symptoms. Common findings for bone marrow sarcoidosis involve cytopenias, lymphadenopathy, and hypersplenism. Treatment involves steroids, and if not responsive, addition of immunosuppressants. It is important to base decision of obtaining a bone marrow biopsy when sarcoidosis is highly suspected in the setting of hypercalcemia.