Crossed renal ectopia with fusion: report of two patients.

Crossed renal ectopia is one of the rarest urinary system anomalies. It is more often seen at autopsy than in clinical practice. Most cases of renal ectopia remain asymptomatic during life and are diagnosed incidentally. Renal ultrasonography, intravenous pyelography, computerized tomography, and renal scintigraphy (technetium-based tests) are the imaging methods used for diagnosis. Demonstration of crossed renal ectopia is important because it is a predisposing factor for obstruction, infection, and neoplasia of the urinary system. We report two male patients who had unremarkable clinical findings. Both had left-to-right inferior crossed renal ectopia with fusion. Additionally, the first patient had a history of surgery for a recurrent inguinal hernia, whereas the second had crossed fused renal ectopia associated with nephroptosis. Surgeons should be aware of ectopic and fused kidneys to minimize perioperative complications because of the uncertain anatomy.