Amyloid arthropathy revealed by RS3PE syndrome

Amyloid arthropathy is a form of primary AL amyloidosis with a monoclonal component in the blood and/or urine, and RS3PE syndrome is acute edematous polysynovitis in subjects older than 60 years. A 74-year-old man was diagnosed with both disorders. He was admitted for benign acute polyarthritis of the hands and feet and reported carpal tunnel symptoms predominating on the right. A synovial biopsy at the right wrist disclosed deposits that stained with Congo red even after potassium permanganate treatment (positive Wright's test). Articular AL amyloidosis was diagnosed. The symptoms resolved under glucocorticoid therapy alone, casting some doubt on their relationship with the amyloidosis. Roentgenograms showed geodes, a feature not present in RS3PE. Whether RS3PE may be among the possible presentations of articular amyloidosis is discussed.