Granulomatosis with Polyangiitis (GPA) (Previously known as Wegener's Granulomatosis) By Alexandra Villa-Forte, MD, MPH, Cleveland Clinic Reviewed / Revised Jun 2022 | Modified Sep 2022 View Patient Education Pathophysiology Symptoms and Signs Diagnosis Prognosis Treatment Key Points Topic Resources Saddle Nose Deformity in... Granulomatosis with Polyangiitis... Granulomatosis with Polyangiitis... Granulomatosis with polyangiitis is characterized by necrotizing granulomatous inflammation, small - and medium-sized vessel vasculitis, and focal necrotizing glomerulonephritis, often with crescent formation.