The "nutcracker phenomenon" with orthostatic proteinuria: case reports.

The nutcracker phenomenon refers to compression of the left renal vein between the aorta and the superior mesenteric artery. Clinical features are hematuria, abdominal pain, left flank pain, pelvic or scrotal discomfort due to varicocele or ovarian vein syndrome. In this report, 2 patients with orthostatic proteinuria, in whom nutcracker phenomenon was detected as a cause, are presented. One of them had posterior nutcracker with also asymptomatic varicocele that was detected during ultrasonographic examination. Nutcracker phenomenon is a rare but important clinical condition that should be considered in the differential diagnosis of patients with proteinuria and hematuria.