Biopsy diagnosis of systemic vasculitis.

A definitive diagnosis of virtually all vasculitides requires histological documentation. Although each major type of systemic vasculitis may have its own unique features, variability and overlaps still exist, and histopathological specificity is rarely an absolute discriminator. The interpretation of biopsies for the diagnosis of vasculitis remains more an art than a science, and it requires full and complete correlation with historical, clinical, laboratory, and angiographic findings.