Vasculitis

Abstract

The pathology of pulmonary vasculitis is a complex and confusing subject for several reasons: (1) In virtually all the idiopathic vasculitis syndromes, accurate diagnosis requires careful correlation with clinical and laboratory data and cannot be based on histopathologic findings alone. (2) The histopathologic manifestations of idiopathic vasculitis syndromes vary depending on when in the course of disease a biopsy specimen is obtained; lung biopsies, therefore, may have atypical pathologic manifestations that do not meet the traditional diagnostic criteria. (3) The differential diagnosis is complex and includes rare systemic diseases with which few pathologists have much experience. (4) Because necrotizing granulomatous inflammation is a frequent feature of the pulmonary idiopathic vasculitis syndromes, the pathologic manifestations can be mimicked by granulomatous infections. Thus, it is important to distinguish idiopathic vasculitis syndromes from infectious processes because the former are often treated with immunosuppressive agents. (5) The pathogenesis of these disorders varies greatly and is poorly understood. © 2008 Springer New York.