Incidentally discovered renal arteriovenous malformation

A healthy 42-year-old woman presented proteinuria and hematuria on regular medical check-up two years ago. Her other laboratory examinations did not show any abnormal findings, including renal function, anti-neutrophil antibody, anti-neutrophil cytoplasmic antibody, C3, C4, or immunoglobulin. Her blood pressure was also normal. Because flank pain had developed, color Doppler ultrasound of the kidney was performed. There was a 2-cm-sized renal cyst with blood flow in the right kidney (Fig. 1). Computed tomography angiography and renal angiography demonstrated it to be a renal arteriovenous malformation (RAVM) (Fig. 1, 2). Based on the size of the malformation, its location, and symptoms of the patient, we planned elective endovascular treatment. Successful