A rare cause of hydronephrosis: Left retrocaval ureter without situs inversus or inferior vena cava duplication with CT and US imaging findings.

Retrocaval ureter is a rare congenital anomaly. It usually occurs on the right side and cases on the left side without accompanying conditions such as situs inversus or double inferior vena cava (IVC) are uncommon. Instances of left retrocaval ureter without situs inversus or double IVC are rarely reported in the literature, and there are no cases presented sonographically. In this case, we present a demonstrative sonographic and tomographic images of a left-sided Type 1 retrocaval ureter case where situs inversus and double IVC were not present. In cases where hydronephrosis is detected on ultrasound, a medially displaced ureter should raise suspicion for retrocaval ureter.