Crossed fused renal ectopia: Diagnosis and prognosis as a single-center experience

Tandem Kidney: A Case of Left Crossed Fused Renal Ectopia

“…[11] The heterotopic kidneys are usually hypoplastic and hypofunctional compared to their orthotopic counterparts. [6,7] Adrenal glands appear to be normal in this case of the tandem kidney.…”

“…It is largely an incidental finding when patients are evaluated for other conditions, or during antenatal or postnatal screening ultrasonography. [6][7][8] 85-90% of crossed renal ectopias appear fused either partially or fully with the contralateral kidney with a male preponderance. [8] Unilateral crossed renal ectopia, bilateral crossed renal ectopia, crossed fused renal ectopia, and crossed unfused renal ectopia are the four forms of crossed renal ectopia described in the literature.…”

“…[3] An anterior and/or posterior notch, two distinct collecting systems and empty contralateral renal fossa are characteristic ultrasonographic findings of crossed fused renal ectopias. [6,7] (Figure 2) depicts the schematic representation of the classification of crossed renal ectopia and the subtypes of crossed fused renal ectopia.…”

“…Crossed fused renal ectopia can be associated with urinary and extra-urinary abnormalities such as anorectal anomalies (imperforate anus), vaginal agen-esis, penile duplication, cryptorchidism, [6] intestinal malrotation, VACTERL association (vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, and limb abnormalities), and TAR syndrome (Thrombocytopenia with the absence of Radius), [3] meningomyelocele, spinal cord tethered syndrome, etc. Double nutcracker syndrome has been found to be associated with the tandem kidney.…”

“…[4] Most renal abnormalities can be evaluated using Multi-Detector Computed Tomographic (MDCT) urography. [9] Renal complications such as vesicoureteral reflux, urinary tract infection, calculus, hydronephrosis, megaureter, ureteropelvic junction obstruction, [6] cystic dysplasia, neoplasms such as Wilm's tumor, transitional cell carcinoma, and renal cell carcinoma are predisposed by crossed renal ectopias. [6,10] Crossed fused renal ectopia should be examined and followed upon to better patient care and minimize complications.…”