Illustrated histopathologic classification criteria for selected vasculitis syndromes. American College of Rheumatology Subcommittee on Classification of Vasculitis.

We describe the histopathologic criteria for the diagnosis of 7 selected vasculitis syndromes: polyarteritis nodosa, Churg-Strauss syndrome, Wegener's granulomatosis, hypersensitivity vasculitis, Henoch-Schönlein purpura, giant cell (temporal) arteritis, and Takayasu arteritis. The criteria apply to the stereotypical cases in each category; they were formulated after a review of submitted biopsy material from 278 of the 1,000 patients entered into the American College of Rheumatology Vasculitis Study Registry, and from prior experience with the pathologic diagnosis of vasculitis in 1,079 nonregistry patients.