[Malignant rheumatoid arthritis].

Malignant rheumatoid arthritis (MRA) is a name for rheumatoid arthritis (RA) complicated with systemic vasculitis or other severe extra-articular manifestations, which can cause a fatal outcome. MRA is found in 4-5% of inpatients with RA. The male to female ratio is 1:1.45. Histologically, 3 main types are recognised in rheumatoid vasculitis; RA type (vasculitis with rheumatoid nodule-like appearance), PN type (fibrinoid vasculitis similar to PN), and EA type (endoarteritis obliterans). High titers of rheumatoid factor, immune complexes, hypocomplementemia, hypoproteinemia, decreased choline esterase activity, elevated alkaline phosphatase activity and leukocytosis are characteristic laboratory features of MRA. Recently, it appears that MRA is becoming less and the prognosis is getting better, perhaps due to the advancement in treatment.