Bilateral supernumerary kidneys: how much is too much?

Area of Science:

• Nephrology
• Metabolic Disorders
• Urology

Background:

• Carnitine palmitoyl transferase II (CPT II) deficiency is a rare genetic disorder affecting fatty acid metabolism.
• Patients with CPT II deficiency are susceptible to metabolic decompensation during physiological stress.
• Supernumerary kidneys are a rare congenital anomaly with potential complications.

Observation:

• A middle-aged African-American woman with known CPT II deficiency presented with myalgias.
• Clinical findings indicated severe sepsis secondary to pyelonephritis, leading to rhabdomyolysis.
• Abdominal CT revealed bilateral supernumerary kidneys with non-obstructive calculi.

Findings:

• The patient's pyelonephritis, stemming from abnormal ureteral development in supernumerary kidneys, triggered rhabdomyolysis by overwhelming her CPT II enzyme capacity.
• Management included intravenous fluids, antibiotics, and a carbohydrate-rich, low-fat diet to minimize fatty acid oxidation.
• Follow-up revealed obstructive ureteral calculi requiring ureteral stent placement.

Implications:

• This case underscores the importance of considering congenital anomalies in patients with metabolic disorders presenting with severe illness.
• Abnormal renal anatomy, such as supernumerary kidneys, can predispose individuals to urinary tract infections and subsequent metabolic crises.
• Early recognition and management of UTIs in patients with CPT II deficiency are crucial to prevent severe complications like rhabdomyolysis.