Histopathological characteristics of early rheumatoid arthritis: a case one month after clinical onset

Abstract

A 68-year-old woman with early rheumatoid arthritis (RA) was admitted to the hospital because of tender and swollen knee joints. We performed a targeted synovial biopsy under arthroscopy to examine the histopathological characteristics 1 month after clinical onset. The synovia showed the typical histopathology of RA. Although the inflammatory changes were predominantly limited to the surface area of the synovia, associated with neovascularization and cell infiltrates composed mainly of T cells, plasma cells, and macrophages, lesions with fibrin deposition, mesenchymoid transformation and/or immature lymphoid follicles were also observed in part, indicating that this case was in the progression phase of RA. What we regularly call "early" might be "too late" even if it is within 1 month of clinical onset.