Introduction: Abdominal pain and flank pain cause a significant proportion of emergencydepartment (ED) visits. The diagnosis often remains unclear and is frequently associated withrepeat visits to the ED for the same complaint. A rare cause of left upper abdominal and flank painis compression of the left renal vein between the aorta and the superior mesenteric artery known asnutcracker syndrome. Diagnostic findings on ultrasound include increased left renal vein diameterproximal and peak blood flow velocity increase distal to the superior mesenteric artery. We describesuch a patient presenting to an ED repeatedly with severe pain mimicking renal colic before the finaldiagnosis and intervention occurred.

Case Report: A 16-year-old female, long-distance runner presented four times complaining ofintractable left upper quadrant abdominal pain radiating to the left flank after exercise. On each visiturinalysis revealed proteinuria and hematuria, and on two visits abdominal computed tomographyrevealed no kidney stone or dilatation of the collecting system. Ultimately, she was referred tovascular surgery where Doppler ultrasonography was used to diagnose left renal vein compression. Transposition of the left renal vein improved Doppler diameter and flow measurements andeliminated symptoms.

Conclusion: Emergency physicians must maintain a large list of possible diagnoses during theevaluation of abdominal and flank pain with a repetitive and uncertain etiology. Nutcracker syndromemay mimic other causes of abdominal and flank pain such as renal colic and requires appropriatereferral.