Necrotizing arteritis of the vermiform appendix. A clinicopathologic study of 12 cases.

Necrotizing arteritis of the vermiform appendix (NAVA) is an uncommon condition. There are conflicting reports in the literature about its relationship to systemic polyarteritis nodosa (PAN). In this study, 12 cases of NAVA are described, constituting 0.28% of histologically examined appendixes. Nine of the patients were followed up for a mean of 6.8 years. Systemic necrotizing arteritis was found in three cases, all of which were complicated by secondary ulceration or infarction of the colon. The results strengthen the association between NAVA and systemic PAN. However, it is more meaningful to relate NAVA to the broader group of necrotizing vasculitides rather than exclusively to classic PAN.