Osseous sarcoidosis: a case series

Sarcoidosis is an inflammatory disorder characterized by noncaseating granulomas infiltrating affected organs. Any organ system can be involved, and more than 90 % of patients have a primary pulmonary manifestation. The incidence of radiographically evident bone involvement has been reported over a wide range: from 3 to 39 % depending on the population studied and imaging modalities used. Any bone may be affected in osseous sarcoidosis. Bilateral involvement of the phalanges of the hand and feet is most common. However, reports of long bone, skull, rib and vertebral involvement have appeared. To date, there are no specific tools for the assessment of skeletal disease activity in sarcoidosis. Plain radiograph picks lesions in the small bones of hands and feet greater than does in other bones. Bone scan is useful for defining the extent of the skeletal disease and bone marrow involvement. Magnetic resonance imaging usually demonstrates multifocal lesions within the vertebrae that are hypointense on T1-weighted images and hyperintense on T2-weighted images. In cases of multifocal bone lesions and an established diagnosis of sarcoidosis, a diagnosis of bone sarcoidosis should be considered in the differential diagnosis. Optimal treatment of osseous sarcoidosis remains controversial. We present five cases of multisystem sarcoidosis with skeletal involvement including long bones and vertebrae and a description of immunosuppressive therapies used in our patients. A literature review highlighting the diagnostic approach using radiographic imaging, as well as treatment strategies, is provided.