A Potential Link: Cross-fused Renal Ectopia With Concomitant Absent Left Testicle.

Cross-fused renal ectopia (CFRE) is a rare congenital anomaly in which both kidneys are located on a unilateral side of the retroperitoneal space. The ureter of the ectopic kidney is seen to pass over the midline to insert in its normal anatomic position. Frequently this anomaly goes undetected until there is radiologic screening for other purposes or when other genitourinary issues are investigated. Although frequently isolated, this condition has been reported to be associated with other congenital anomalies, genetic disorders, and various urogenital anomalies more than 50% of the time. However, we found no cases linking CFRE with a solitary testicle. This is a case of a 30-year-old man with left-to-right CFRE with concomitant absent left testicle and obstructing distal calculus.