A small-vessel necrotizing vasculitis characterized by the association of inflammation of the vessel wall and peri- and extravascular granulomatosis. The disease is granulomatosis with polyangiitis (MONDO_0012105). Also known as: GPA, Wegener granulomatosis, Wegener's granulomatosis, Wegener's syndrome, granulomatosis - Wegener's, necrotizing respiratory granulomatosis, pauci-immune glomerulonephritis associated with granulomatosis with polyangiitis.