[Joint swelling, reversible arm paresis, and elevated serum IgG4 in a 55-year-old man].

Only described in the last 10 years, IgG4-related disease is a fibroinflammatory disorder characterized by tumorous lesions with dense lymphoplasmacytic infiltration by IgG4-positive plasma cells and often elevated concentration of serum IgG4. In this paper, we present a male patient with this disease involving the lymph nodes and possibly the joints and kidneys. Infiltration of lymph node tissue with IgG4-positive plasma cells was demonstrated. The general condition of the patient improved considerably by immunosuppressive therapy.