[A case of pigmented villonodular synovitis of the elbow joint with bone invasion].

Pigmented villonodular synovitis is a benign proliferative disorder of the joint and of the tendon sheath synovium. It has a predilection for the lower extremities, particularly the knee and the hip. The elbow joint is rarely affected. A 56-year-old woman had complaints of pain and swelling in the left elbow for three years. She had no history of trauma. On physical examination, she had swelling of the left elbow, varus deformity, and flexion contracture of 20 degrees. Active and passive joint movements were painful. Magnetic resonance imaging showed synovial thickening and signal changes. An incisional biopsy yielded a diagnosis of pigmented villonodular synovitis. She underwent subtotal synovectomy and excision of the radius head. No evidence of clinical or radiologic recurrence was detected within a follow-up of 16 months.