Intra-articular fibroma of tendon sheath of the shoulder joint: synovial fibroma.

The case of a 30-year-old woman with multiple loose bodies in the shoulder joint is presented. The patient complained of discomfort of her right shoulder. Conventional radiographs failed to reveal any abnormality of the shoulder. On MRI numerous loose bodies were detected that resembled synovial chondromatosis. Histologically, the loose bodies were composed of a benign fibroblastic lesion with diagnostic features of fibroma of tendon sheath, each surfaced by synoviocytes. The clinicopathologic features of intra-articular fibroma of tendon sheath are reviewed. We propose using the term "synovial fibroma" for tumors with histopathologic features of fibroma of tendon sheath arising in the synovium of joints.