ABSTRACT
Nutcracker syndrome is caused by external compression of the left renal vein and is characterized by various symptoms, such as hematuria and left flank pain. However, long-standing gross hematuria is uncommon. We report the case of a 23-year-old woman who had had painless gross hematuria for several months. Kidney biopsy revealed thin basement membrane disease, but this did not explain the gross hematuria with proteinuria. Renal venography and Doppler ultrasonography showed increased diameter and velocity ratios between the left renal vein and inferior vena cava. Cystoscopy revealed that the hematuria originated from the left ureteral orifice. These results indicate coexisting Nutcracker syndrome. Nutcracker syndrome with thin basement membrane disease should be considered in the differential diagnosis of a patient who has long-standing gross hematuria.