Crossed Renal Ectopia with a Fused Supernumerary Kidney

Area of Science:

• Urology
• Congenital Anomalies
• Medical Imaging

Background:

• Crossed fused renal ectopia and supernumerary kidneys are rare congenital urinary tract anomalies.
• These conditions can be asymptomatic or associated with other developmental abnormalities.
• Early diagnosis is crucial for managing potential complications.

Observation:

• A 20-year-old male with a history of imperforate anus and tethered spinal cord presented with flank pain.
• Initial imaging suggested crossed fused renal ectopia.
• Computed tomography (CT) revealed a more complex anomaly: a supernumerary kidney fused to the right kidney, which was then fused to an orthotopic left kidney.

Findings:

• The patient had a 4-mm distal left ureteral stone.
• A supernumerary kidney was found fused to the right kidney, which was also fused to the orthotopic left kidney.
• This complex renal fusion anomaly was not detected by prior nuclear medicine renal scans or ultrasounds.

Implications:

• Highlights the importance of advanced imaging like CT in diagnosing complex congenital anomalies.
• Underscores the potential for misdiagnosis of rare renal variations with standard screening methods.
• Emphasizes the need for comprehensive evaluation in patients with multiple congenital anomalies.