Question of the Week
For September 30, 2014
A 45-year-old woman presents with nodular growths over her right elbow. She has a history of rheumatoid arthritis, which has been treated successfully with methotrexate. Hand radiographs have confirmed the presence of erosions, and a rheumatoid factor test in the past year was positive.
The patient is comfortable, without evidence of active synovitis. She has discrete, mildly erythematous, mildly tender nodules on the extensor surface of her right elbow joint (figure). The range of motion for the elbow is normal.
Which one of the following diagnoses is most likely in this case?