类风湿关节炎（RA）引起的手畸形。这种自身免疫病导致滑膜增生与关节破坏，典型病变为对称性畸形，出现于手与足的小关节，其次是腕关节、踝关节、肘关节、膝关节。血清学检测，大部分(并非全部)病人可查到类风湿因子。
类风湿关节炎：手畸形 肘结节(肉眼) 结节(低倍镜) 滑膜炎血管翳(低倍镜)
This deformity of the hand is due to rheumatoid arthritis (RA). This autoimmune disease leads to synovial proliferation and joint destruction, typically in a symmetrical pattern involving small joints of hands and feet, followed by wrists, ankles, elbows, and knees. Rheumatoid factor can be identified serologically in most, but not all, RA patients.