Primary Rosai-Dorfman Disease of the Proximal Radius Masquerading as Tuberculosis of Elbow.

A 36-year-old female presented with pain and progressive decrease in the range of movements in the left elbow. There was contact with an open case of pulmonary tuberculosis. There were no constitutional symptoms except fever. X-ray showed periarticular osteopenia with destruction of the radial neck and head. MRI scan findings were also consistent with tuberculosis of the elbow. Histopathology examination confirmed the diagnosis of Rosai-Dorfman disease. The patient was treated with glucocorticoid and methotrexate and was asymptomatic after 18 months.