Uncracking a Case.

Nutcracker phenomenon (NCP) refers to compression of the left renal vein (LRV), most frequently between the aorta and the superior mesenteric artery, with impaired blood outflow often accompanied by distention of the distal portion of the vein. The nutcracker syndrome (NCS) is the terminology used when the nutcracker phenomenon is accompanied by a complex of symptoms such as pain (abdominal, flank, and pelvic), hematuria and orthostatic proteinuria. Diagnosis can be made with Doppler ultrasound (DUS), computed tomography (CT), magnetic resonance imaging (MRI), and venography.