Multiple renal infarctions in a patient caused by granulomatosis with polyangiitis.

Granulomatosis with polyangiitis (GPA) is a small-vessel vasculitis that is highly associated with anti-neutrophil cytoplasmic antibodies. GPA carries an increased risk of organ infarction, but renal infarction is rare. We herein describe a case of multiple renal infarctions caused by GPA. A 66-year-old man presented with hearing loss, nasal discharge, fatigue, and weight loss for several months. Cross-sectional contrast-enhanced computed tomography images revealed multiple low-attenuation areas in both kidneys. He subsequently developed fever and impaired renal function. Blood serum was positive for cytoplasmic anti-neutrophil cytoplasmic antibody and a renal biopsy showed granulomatous necrotizing vasculitis. He was diagnosed with GPA and treated with high-dose corticosteroids, plasma exchange, and cyclophosphamide. The patient ultimately entered clinical remission.