Fig. 1

Unusual clinical presentations of anti-neutrophil cytoplasmic antibody-negative eosinophilic granulomatosis with polyangiitis. a Our patient showing left periorbital swelling, possibly representing an orbital inflammatory pseudotumor. b The apical chamber view of a transthoracic echocardiogram shows a significant pericardial effusion. c Fluid drained from the pleural effusion contained 77% eosinophils. d Biopsied lung tissue shows marked infiltration by eosinophils, with eosinophils infiltrating the walls of small vessels, the submucosa of an adjacent small airway, and the interstitium. e Pericardial tissue shows significant infiltration by both eosinophils and plasma cells. d and e Hematoxylin and eosin, × 400. LV left ventricle, PE pericardial effusion, RV right ventricle