[Nutcracker Syndrome with Left Inferior Vena Cava : A Case Report].

A 37-year-old male with a history of intermittent gross hematuria visited our hospital with asymptomatic macrohematuria. Cystoscopy findings revealed bloody urine from the left ureteric orifice and the cytodiagnosiswasclas sII. Contrast-enhanced computed tomography imaging revealed the inferior vena cava (IVC) running upward along the left side of the aorta, then crossing the aorta between the aorta and superior mesenteric artery (SMA). The crossing portion of the IVC was severely compressed by the SMA, causing the left-sided IVC (LIVC), and two left renal veins (LRV) were entered at the dilated portion of LIVC. On suspicion of nutcracker syndrome (NCS) with LIVC, color doppler ultrasonography and venography examinationswere performed. Although the resultsdid not meet criteria reported for NCS, venography revealed reflux from the IVC to the upper branch of the left renal vein. LIVC is a rare vessel anomaly, with a rate of incidence ranging from 0.2-0.5%, while NCS with LIVC isextremely rare, with only 7 case reports in the English literature. Herein. we report the first known case in Japan and review previous reports.