Osseous sarcoidosis: Clinical, radiographic, and therapeutic observations

Sarcoidosis is a systemic inflammatory disease of unknown etiology characterized by abnormal T cell function. Osseous involvement is found in approximately 5% of patients with sarcoidosis. Although sarcoidosis predominantly affects the small bones, it may involve other parts of either the axial or appendicular skeleton. Patients with osseous sarcoidosis are often asymptomatic, which frequently makes diagnosis difficult. Radiographic findings may be suggestive of focal bone involvement requiring bone scintigraphy and or magnetic resonance imaging (MRI) to exclude other important clinical concerns. We present two histopathologically confirmed cases of osseous sarcoidosis that underscore the heterogeneous presentation of bone involvement and highlight potential relationships to markers of disease activity, including the erythrocyte sedimentation rate and serum angiotensin converting enzyme level. In these cases, plain radiographs identified focal symptomatic changes suggestive of osseous disease; bone scintigraphy identified the extent of osseous involvement; and MRI quantified the degree of soft tissue, articular, and osseous inflammation. Treatment of osseous sarcoidosis remains problematic because there are few prospective studies to guide clinicians. Corticosteroids, nonsteroidal anti-inflammatory drugs, hydroxychloroquine, cyclosporine A, and methotrexate have all been used in extra-pulmonary sarcoidosis with varying success. In our experience, concomitant therapy with indomethacin and hydroxychloroquine was effective in treating both pain and dactylitis in patients with osseous sarcoidosis. The effect these agents have on actual bone infiltration in osseous sarcoidosis is not known.