For years the group of disorders generally referred to as the necrotizing angiitides have been a source of confusion to both pathologists and clinicians. The lesions can have many forms, produce a host of different symptoms, and can accompany a variety of apparently unrelated clinical conditions.
Since "periarteritis nodosa" was first described by Kussmaul and Maier in 1866,1 the meaning of the term has changed considerably. A subsequent proliferation of reports has broadened and somewhat obscured the original definition, so that today the term periarteritis nodosa, or "polyarteritis nodosa," is applied rather loosely by some as a histologic description to many necrotizing arterial lesions, while it is reserved by others for a clinical syndrome of which the arterial lesions are a feature. Perhaps the most widely used terminology currently applied to the angiitides is that proposed by Zeek in 1952,2 though there are many cases which cannot wholly