Crossed Fused Renal Ectopia with Single Ureter and Single Renal Vein: A Rare Case

Crossed fused renal ectopia with a single ureter and single renal vein is a rare congenital anomaly in which both the fused kidneys lie on one side of the body. We present an unusual case of crossed fused renal ectopia with a single ureter, single renal vein, and a calculus in a 22-year-old man who presented with lower abdominal pain, burning micturition, and a right-side abdominal lump present for three months. On abdominal ultrasound and non-contrast computed tomography (CT), the left kidney was not visualized in the left renal fossa. However, we noted it on the right side, fused to the lower pole of the right kidney with a calculus within the pelvis leading to mild hydronephrosis. After intravenous administration of non-ionic contrast medium, we saw a single ureter draining both the moieties into the urinary bladder on the right side. A three-dimensional volume rendering technique revealed a single renal vein draining the renal parenchyma into the inferior vena cava. Cross fused renal ectopia is an uncommon congenital anomaly which remains asymptomatic throughout life and undetected in the absence of renal pathologies. Multi-detector computed tomography (MDCT) is an excellent tool for denoting anatomical details of this anomaly; the information provided by MDCT is crucial for surgeons, nephrologists, and radiologists alike in facilitating proper management of the condition.