Unilateral Enlarged Kidney

Differential considerations include:

• Obstruction: Most common cause.
• Pyelonephritis:
• Renal vein thrombosis:
• Duplex kidney:
• Compensatory hypertrophy:
• Crossed fused ectopia: One kidney crosses the midline and fuses with the other kidney. The fused kidneys lie to one side of the spine, with the ureter for the crossed kidney crossing the midline to insert into the bladder. More common in males. Left kidney more commonly crosses.
• Tumor:
• Multicystic dysplastic kidney:
• Trauma:
• Acute arterial infarction:

See related post on bilateral enlarged kidneys.