Fact-sheet: Ectopic kidney
Updated on 04/22/2020 at 10:08 AM
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Definition
The kidney is ectopic when it is not located in the lumbar fossa, without having undergone accidental displacement. Ectopia is generally the result of a migration anomaly. There are simple ectopia, crossed ectopia, and horseshoe kidneys.
Clinical features
Asymptomatic, vesicoureteral reflux, calculi, ureteropelvic junction obstruction...
Laboratory findings
Normal
Radiography
Empty renal fossa
Ultrasound
Simple ectopia:
Empty renal fossa
Pelvic, iliac, or rarely intrathoracic kidney
Often associated with malrotation
Renal artery arising from the aorta or the iliac artery
Horseshoe kidney:
Fusion of the lower poles
Anterior malrotation of the renal pelves
Both kidneys in a low position
Proximal ureters crossing the parenchymal isthmus
Crossed ectopia:
Kidney and ureter contralateral to the ureterovesical orifice
In most cases, the ectopic kidney is fused to the contralateral kidney, giving the appearance of a single enlarged kidney with an anteroposterior notch and 2 renal pelves with differing orientations
Ureter crossing the midline
CT
Findings identical to ultrasound, with better delineation of ureteral course and more precise assessment of malformations on CT
MRI
Findings identical to ultrasound and CT
Management
Treatment only if symptomatic or in cases of significant reflux or obstruction.