Iliopsoas bursitis in rheumatoid arthritis.

A 58-year-old woman with rheumatoid arthritis (RA) presented with persistent hip pain and an inguinal mass. Considerable liquid had collected inside the iliopsoas bursa, apparently not in communication with the hip joint, as shown by ultrasonography and computed tomography (CT). After one month of systemic steroidal therapy (25 mg/day prednisone), the palpable inguinal mass and pain had disappeared. Iliopsoas bursitis should be suspected in RA patients with a long history of disease presenting with an inguinal mass, persistent groin pain or unilateral leg swelling. The lack of communication between the hip joint cavity and bursa may be considered as a favourable prognostic index. Steroid treatment should be always attempted in order to avoid surgery.