A Not So Common Iliac Vein Anomaly: A Case Report.

Arising from the external and internal iliac veins, the common iliac veins (CIVs) carry blood from the lower extremities and pelvic region into the inferior vena cava at the level of the fifth lumbar vertebra. It is sometimes common to observe slight anomalies in vascular anatomy in patients; however, anomalies of the CIVs are rare. We present a case of a patient with significant edema of the left lower extremity due to extrinsic compression (May-Thurner syndrome [MTS]) involving a duplicated left CIV found during vascular angiography.