Histopathological differentiation of systemic necrotizing vasculitides

Current consensus classifies systemic vasculitis into several main groups. This classification is based on the type and size of involved blood vessels, the organs or tissues affected, the composition of the inflammatory infiltrate, the clinical presentation as well as on serological and immunological abnormalities. Although its validity will only be confi ied when there is a better understanding of the pathogenesis of systemic vasculitis, our present classification (modified according to Fauci et al. ’) provides a useful guide to prognosis and therapy: