E2024. When Cartilage Goes Rogue: Extra-Articular Synovial Chondromatosis
Authors
Bowen Wei;
University of California, Los Angeles
Kira Chow;
University of California, Los Angeles; VA Greater Los Angeles Healthcare System
Joshua Leeman;
University of California, Los Angeles; VA Greater Los Angeles Healthcare System
Background
Extra-articular synovial chondromatosis is a relatively rare entity characterized by multinodular cartilaginous proliferation involving the synovium of tendon sheaths and bursae. It is the extra-articular counterpart to the more well-recognized synovial (intra-articular) chondromatosis.
Educational Goals / Teaching Points
Recognition of this less common imaging presentation is important for radiologists to avoid its misclassification and misdiagnosis.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The pathophysiology of extra-articular synovial chondromatosis is proposed to be secondary to a benign neoplastic proliferation of the synovium with a strong potential for local recurrence, analogous to the pathogenesis of intra-articular synovial chondromatosis given their similarity in histologic characteristics. Commonly affected body parts consist of synovial spaces of the hands and feet. Presenting symptoms usually include painless enlarging mass with subsequent complaints relate to mass effect of the lesion include pain, pressure, swelling, locking, a limited range of motion, and symptoms secondary to neurovascular compression. The appearances on MRI and radiography vary depending on the extent of ossifications, loose bodies formations, and synovial proliferations. Treatments often comprised of open or arthroscopic synovectomy with debridement and removal of loose bodies and fragments.
Conclusion
Extra-articular synovial chondromatosis is characterized by multinodular cartilaginous proliferation involving the synovium of tendon sheaths and bursae. Its pathophysiology is proposed to be similar to that of synovial (intra-articular) chondromatosis with various nonspecific presenting symptoms. Recognition of this relatively rare entity on imaging is essential for radiologists to avoid its misclassification and misdiagnosis.
