Extra-Articular Soft Tissue and Muscular Involvement in Systemic Lupus Erythematosus

Soft tissue lesions in systemic lupus erythematosus (SLE) include various lesions such as subcutaneous edema, synovitis of the joint, edema of the joint capsule, tenosynovitis, tendon rupture, muscular, and vascular involvement. The synovium of bursa is also affected. Ultrasound and MRI are especially important for the evaluation of soft tissue lesions because of the low sensitivity of conventional radiography. The soft tissue lesions of SLE are diverse and widespread, and understanding their pathophysiology can help diagnose whether the lesions are of SLE origin or a complication of other factors. Knowing the soft tissue lesions of SLE can also help us to deal with the wide variety of lesions in SLE patients. In this article, we summarize the variety of extra-articular soft tissue lesions.