Massive Orbital Infiltration and Trigeminal Enlargement in Churg-Strauss Syndrome Associated With IgG4 Plasma Cell Positivity.

The association of C-antineutrophil cytoplasmic antibody (ANCA) vasculitis and IgG4 positivity is a new condition not well described in clinical terms. The authors examined a 28-year-old man with a previous diagnosis of eosinophilic granulomatosis with polyangiitis, formerly known as Churg-Strauss disease, who presented with bilateral orbital inflammation. Magnetic resonance imaging revealed diffuse orbital infiltration and enlargement of the major divisions of the trigeminal nerve. Biopsy of the orbital contents showed necrotizing granulomatous vasculitis and a high number of IgG4-positive plasma cells (IgG4/IgG = 60%).