LAUSR

A 70-year-old female patient treated with methotrexate for diffuse cutaneous systemic sclerosis (SSc) came up with mechanical pain over the left thumb for several months. SSc was diagnosed based on a clinical picture associating puffy fingers, skin sclerosis, wrist arthralgia, pulmonary hypertension, presence of antinuclear factors and antibodies against Topoisomerase-I. Her complaint was attributed to first carpometacarpal joint osteoarthritis and treated with orthesis, which did not provide pain relief after 5 months of regular use. Hand radiograph showed first carpometacarpal arthropathy with joint space narrowing and marked sclerosis of the first proximal metacarpal (A). MRI showed an area of very low signal intensity on T1- and T2-weighted images (B) within the proximal metacarpal, distal trapezium and medial joint recess surrounded by bone marrow edema. Mild peripheral enhancement was present after gadolinium injection. CT-scan (C) showed that the low signal intensity material visible at MRI consisted of calcium. These aspects are suggestive of scleroderma arthropathy rather than common first carpometacarpal osteoarthritis. Though involvement of the first carpometacarpal joint is long time known in SSc [1], it remains exceptional when looking at cross-sectional studies [2]. Carefully analyzing imaging exams is the key point in order not to miss this rare scleroderma feature.