Monday, May 21, 2012

Unilateral Kidney Enlargement: Differential Diagnosis #18

Various reasons can cause the kidneys to shrink or enlarge, either unilaterally or bilaterally. Having a working differential for each possibility is very helpful. Today's Daily Diff concerns the case of a unilaterally enlarged kidney. The mnemonic device AROMA can be used to recall the common causes of unilateral renal enlargement:

AAcute pyelonephritis
RRenal vein thrombosis
OObstructive uropathyMost be above the bladder/urethra to be unilateral; most common cause
MMiscellaneousex Duplication, hypertrophy, cross-fused ectopia
AArterial obstruction

Severe Acute Pyelonephritis Causing Unilateral Kidney Enlargement
Source: Radiographics