A case report of non-functional ectopic left kidney obstructing the right kidney in crossed fused kidneys: A rare entity

Introduction and importance Crossed fused renal ectopia is a rare congenital condition that might pose some diagnostic and therapeutic challenges to clinicians. We report a patient with a non-functional crossed fused ectopic left kidney that obstructed the orthotopic kidney in a rarely observed situation. Case presentation A 68-year-old male presented a right flank pain with fever. The diagnosis of right obstructive pyelonephritis was dressed, after biological and radiological investigations. The obstacle was a crossed ectopic left kidney in its inferior variety. The ectopic kidney was non-functional as result of an obstructive ureteral calculus. The patient had right ureteral stenting with a double-J catheter. Three months later, left nephrectomy was performed by lumbotomy. Per operative difficulties were mainly the infiltration of peri renal fat, the anarchic vascularization and the multiple small pedicles of the ectopic kidney that was also malrotated with the hilum facing anteriorly. Postoperative recovery was uneventful and the patient left the hospital after three days. Clinical discussion Crossed Fused renal ectopy is rare. As shown in this case, the ectopic kidney might cause damage to the orthotopic kidney, by compression to urinary ducts. Surgery is the main treatment option. Some difficulties related to aberrant vascularization and possible malrotation is to preview. Conclusion Crossed fused renal ectopia is uncommon renal anomaly, mostly asymptomatic. However, it may be responsible of some complications, sometimes severe. Surgery can be delicate due to vascular complexity.
Highlights • Crossed renal fused ectopy is rare and asymptomatic congenital condition. Association to other malformations is possible. • The ectopic kidney may be responsible of the obstruction and the mal function of the orthotopic kidney. • This is the first case to be reported in literature. • Surgery might be difficult due to aberrant vascularization and possible malrotation of the kidney.