CT of the head and orbits showed normal sinuses, bilateral proptosis with increased caliber of the inferior and medial rectus muscles bilaterally (left), and bilateral parotid gland enlargement (below, white arrows). Ophthalmology diagnosed left pan-uveitis and neuroretinitis, which after a negative infectious work-up was thought to be possible vasculitis.
Serologies revealed a C-ANCA of 1:320 and PR3 antibody of 28.5.
The overall clinical picture was consistent with an ANCA-associated systemic vasculitis with both typical (sinus, lung, articular, and renal) and atypical (orbital, parotid, pericardial, conduction system, and mediastinal) features. We diagnosed granulomatosis with polyangiitis (GPA).
VATS biopsy of the left lung mass revealed vasculitis involving the arterioles with resultant angiodestruction, relative sparing of the small arteries, and numerous necrobiotic and angiocentric granulomas (below). Marked fibrosis was present, with positive immunofluorescence for IgG and fibrin within the arterioles, consistent with GPA.