[Retroaortic renal vein. Report of a case].

The retroaortic renal vein is a malformation characterized by the presence of a vessel that drains the left renal blood up to the inferior vena cava crossing behind the aortic artery. Unfamiliarity with this condition may lead to an incorrect diagnosis of adenopathy in patients with testicular and/or renal neoplasia and increases the number of complications of surgery of the left renal pedicle. Herein we describe a 71-year-old male with a retroaortic renal vein that had been detected during radical surgery for a left renal tumor.