A 61-year-old man with known granulomatosis with polyangiitis (GPA; diagnosed on nasal biopsy) presented with a gritty sensation in the left eye, subsequent horizontal diplopia progressive over 1 month, and left ophthalmic and maxillary distribution of trigeminal numbness. A left orbital apex soft-tissue mass diagnosed radiologically (Figure 1) was thought likely to be inflammatory. He was treated with high-dose steroids and 6 courses of intravenous cyclophosphamide, with …