A Rare Case of Bone Marrow Sarcoidosis.

Sarcoidosis is a systemic disease characterized by non-caseating epithelioid granulomas and can affect multiple organ systems, most commonly the lungs. Bone marrow involvement in sarcoidosis is rare and not well-documented. This case report details a 50-year-old female presenting with chronic lower back pain and significant hypercalcemia. Imaging revealed non-obstructive renal stones, liver nodularity, splenomegaly, and lung nodules. Initial treatments included corticosteroids for suspected sarcoidosis. Diagnostic workup, including bronchoalveolar lavage and various malignancy markers, was negative. A bone marrow biopsy showed non-caseating granulomas, confirming bone marrow sarcoidosis. This case underscores the importance of considering bone marrow involvement in patients with extrapulmonary sarcoidosis symptoms and highlights the need for a high index of suspicion among healthcare providers. Corticosteroids remain the primary treatment, with ongoing research into alternative therapies.