The eosinophilic variant of Wegener's granulomatosis.

Four cases of an unusual histologic variant of Wegener's granulomatosis, diagnosed by open lung biopsy, are described. In addition to pathergic necrosis, granulomatous inflammation, and vasculitis, intense stromal eosinophilia was observed in the absence of peripheral blood eosinophilia or clinical asthma. A microangiitis was also present in all four cases. Clinically, all patients presented with systemic disease and responded to immunosuppressive therapy including steroids and cyclophosphamide. This form of Wegener's disease poses problems in its distinction from allergic angiitis and granulomatosis, and the differential diagnosis of these two entities is discussed.