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Synovial pathology in rheumatoid arthritis

Ellen M Gravallese, MD
Ratnesh Chopra, MD
Section Editor
Ravinder N Maini, BA, MB BChir, FRCP, FMedSci, FRS
Deputy Editor
Paul L Romain, MD


No single histologic feature or group of features in synovium is diagnostic of rheumatoid arthritis (RA). Many of the histologic changes that are seen can also occur in other inflammatory joint diseases and even in osteoarthritis. Thus, the diagnosis of RA is made by history and physical examination of the patient, and is supported by the presence of characteristic pathologic findings in synovial tissue. (See "Diagnosis and differential diagnosis of rheumatoid arthritis".)

There has been a resurgence of interest in the study of synovial tissue in RA over the past several years. Synovial tissue obtained at joint replacement surgery as well as needle and arthroscopic biopsy samples from patients with RA have been examined by molecular and immunohistochemical techniques in order to gain a better understanding of the pathogenic events in this disease. In addition, synovial biopsies are being used to assess the effects of medical interventions on the production of cytokines, joint-damaging enzymes, adhesion molecules, and other inflammatory mediators [1].

An overview of the histologic features of normal synovium and the changes that are characteristic of RA is presented first, which is followed by a discussion of the synovial response to treatment.


The synovial tissue that lines the fibrous capsule of a joint is derived from cells of the embryonic mesenchyme [2]. Three types of subintima have been described: fibrous, adipose, and areolar [3].

In the normal state, the synovium is a thin membrane that attaches to skeletal tissues at the bone-cartilage interface, and does not encroach upon the surface of articular cartilage. The synovial membrane is divided into two layers:


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Literature review current through: Sep 2016. | This topic last updated: Jul 29, 2016.
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