The diagnostic significance of certain histopathologic changes for rheumatoid arthritis.

As a practical and unequivocally pathognomonic sign for RA could serve a histopathologic change which both displays a conspicuous morphologic distinctiveness and occurs with an overwhelming frequency in RA versus an insignificant or absent frequency in other categories of synovitis. Such postulates were not fulfilled by any of the herein described histopathologic changes. Therefore, no absolutely or indisputably pathognomonic feature may be asserted for RA, although it must be recognized that highly suggestive or indicative significance has to be acknowledged for some of the herein listed histopathologic changes of the synovial membrane.