Crossed-fused renal ectopia with renal calculi and its management, a case report

Crossed fused renal ectopia is a rare congenital anomaly characterized by both kidneys being fused together on one side of the spine. Herein, we present an atypical subtype of this disease. To our best knowledge, in the current literature, there is few cases reported with superior crossed fused renal ectopia of the right kidney. A 40-year-old man with diabetes type 1 presented to our hospital with diabetic ketoacidosis and abdominal pain initially taken care of in an endocrinology department then transferred to our urology department after discovery on the CT scan of a staghorn calculus in the solitary right kidney is later discovered during the therapeutic management that it is a superior CFRE. Unilateral fused renal superior ectopia is extremely rare and the management of urinary calculi in this disease is technically challenging for urologists. The choice of treatment for urinary calculi in cases of crossed renal ectopia should be made depending on the size and position of the urinary calculi and the patient's anatomy. Before proceeding to surgery, a preoperative assessment with contrast computed tomography is necessary to explore a solitary kidney with calculi so as not to miss the diagnosis of crossed fused renal ectopia because the management of renal stone in this rare malformation is complicated. •Unilateral fused kidney superior ectopia is extremely rare.•The diagnostic challenges in crossed fused renal ectopia.•The management of urinary calculi in patients with crossed renal ectopia is technically challenging for urologists.