An Incidental Finding of Retrocaval Ureter Causing Hydroureteronephrosis.

Retrocaval ureter is a rare, congenital anomaly of the inferior vena cava. Due to an abnormal process in embryogenesis, the ureter descends posterior to the inferior vena cava. Although the anomaly can be found in pediatric patients, it most commonly manifests symptoms between the third and fourth decade of life that are typically due to ureteric obstruction, such as hydronephrosis.