Das differenzialdiagnostische Spektrum der Synovialitis

Abstract

This review will suggest an algorithm for standardised histopathological diagnosis of synovial biopsies and synovectomy specimens. In principal, changes of the synovial membrane can be inflammatory or non-inflammatory. To the latter group belong some benign tumors, such as tenosynovial giant cell tumor, lipoma or synovial chondromatosis. Rare non-inflammatory changes are the group of storage diseases. Inflammatory synovial diseases can be differentiated into crystal-induced arthropathy, such as gout and pseudogout, granulomatous diseases, such as tuberculosis, sarcoidosis and foreign body reactions and into the large group of non-granulomatous synovitis. This last group is by far the most common and often causes difficulties in assigning the histopathological findings to a definite diagnosis. Therefore, the synovitis score should be applied in these cases as a diagnostic means, leading to the diagnosis of low-grade synovitis (which is associated with degenerative and posttraumatic arthropathies) or high-grade synovitis (associated with rheumatic diseases), the sensitivity and specificity being 60.5% and 95.5%, respectively. In detritus synovitis the synovitis score is not applicable.