HISTORY: 33-year-old female with history of scleroderma who complains of left hand pain.

RADIOLOGICAL FINDINGS: Plain radiographs of the left hand demonstrate juxta-articular osteoporosis. Marginal erosions are visualized at the 5th DIP joint and 2nd, 3rd, and 4th PIP joints. Central erosion is visualized at the 2nd MCP. There is also erosion of the ulnar styloid. The lunate demonstrates abnormal sclerosis and collapse. The first and second fingers demonstrate distal tuft resorbtion. Punctuate calcifications are visualized in the soft tissues the first finger. There is soft tissue atrophy of the first through fifth fingers.

DIAGNOSIS: Scleroderma with features compatible with mixed connective tissue disease

DISCUSSION: Mixed connective tissue disease (MCTD) is characterized by a combination of features of systemic lupus erythematosus (SLE), scleroderma, and in some cases rheumatoid arthritis. Although the disease is usually defined by serology (high titers of ribonucleoprotein antibodies), if at least one feature of scleroderma and at least one feature of systemic lupus erythematosus (SLE) are present, the diagnosis can be made radiographically. The radiographic features of lupus include osteoporosis, osteonecrosis, and subluxations. The features of scleroderma include distal tuft resorbtion and soft tissue atrophy and calcification. As noted above, one may see the joint space loss and erosion characteristic of rheumatoid arthritis although incontrast to the typical pattern of rheumatoid arthritis, the erosive disease may be seen at the DIP joints in addition to the PIP, MCP, midcarpal and erosion is seen at the second MCP. The distribution may be symmetric or asymmetric. Preferential ankylosis of the capitate and trapezoid is a unique feature of MCTD. Erosive disease due to scleroderma without MCTD can be seen.

REFERENCES:
Resnick D. Bone and Joint Imaging, Philadelphia: W. B. Saunders, 1998 .

Brower A. Arthritis in Black and White. Philadelphia: W. B. Saunders, 1998.