A 31 yr old female under treatment for systemic lupus erythematosus complained of episodes of atypical chest pain radiating to the back. Subsequently she suddenly collapsed and died. Post mortem revealed a well-defined, localized area of non-giant cell aortitis extending from the supra-aortic ridge of the aortic valve to the ligamentum arteriosum. Active arteritis with fibrinoid necrosis and obliterative endarteritis of vasa vasorum had resulted in multiple infarcts of differing ages with associated inflammation and disruption of the aortic wall, culminating in aortic dissection and cardiac tamponade.