At high power, the vasculitis is seen to involve a renal artery branch. This is a necrotizing granulomatous vasculitis. In this case, the anti-neutrophil cytoplasmic autoantibody (ANCA) serology was positive (with prominent cytoplasmic staining of neutrophil granules with proteinase 3, or cANCA pattern) and a diagnosis of ANCA-associated granulomatous vasculitis was made. This patient also had pulmonary involvement with this disease.