Horseshoe kidney with a circumcaval ureter.

Horseshoe kidney accompanied by a totally circumcaval ureter has rarely been reported in the same patient. However, both entities are well recognized as being uncommon anomalies of the genitourinary system. Variability in the normal course of the ureter makes it difficult to differentiate a normal variant from a congenital anomaly or a deviation due to other factors such as inflammation or cancer. We present a case of simultaneous horseshoe kidney and a right ureter that ran in a circular fashion (360 degrees) around the inferior vena cava. Contrast-enhanced CT showed that the ureter passed posterior and medial to the inferior vena cava, providing the definitive diagnosis.