UNILATERAL RENAL AGENESIS

Unilateral renal agenesis is three to four times more common than bilateral renal agenesis.

  • Males = Females.
  • Associated additional genitourinary malformations are frequent and rarely life threatening.

 

ULTRASOUND (1-4)


 

  • Unilateral empty renal fossa.
  • No renal ectopia.
  • Abnormalities of the remaining kidney have been described in up to 90% of patients.
    1. The most common abnormality is vesicoureteral reflux.
    2. Others include renal ectopia and malrotation, ureteropelvic junction (UPJ) obstruction, duplication, and multicystic dysplasia (4).
  • Enlarged contralateral kidney.
  • Adrenal gland on the side of the agenesis may enlarge and attain a renniform shape.
  • Normal amniotic fluid volume (unless there is an abnormality of the contralateral kidney).
  • Color doppler of the renal arteries helps confirm unilateral agenesis.

 


Postnatal Diethylenetrianine pentaacetic acid nuclear medicine scan of the above case demonstrating unilateral left renal agenesis

 

 

 

Video clip of Unilateral Renal Agenesis

 

 

 

PITFALLS IN THE DIAGNOSIS
  • Renal ectopia (pelvic kidney) (1).
  • Crossed fused renal ectopia (enlarged and lobulated kidney) (1,2).
  • An empty renal fossa is usually filled by loops of bowel that should be differentiated from a cystic renal anomaly (3).

 

 

 

 

SYNDROMES ASSOCIATED WITH UNILATERAL

OR BILATERAL RENAL AGENESIS
  • Mayer-Rokitansky-Kuster-Hauser syndrome.
  • Diabetic embryopathy.
  • Smith-Lemli-Opitz syndrome.
  • Fraser syndrome.
  • Caudal regression syndrome.
  • VATER syndrome.
  • MURCS assocition.
  • Branchio-oto-renal syndrome
  • Fanconi pancytopenia
  • Kallman syndrome,

 

REFERENCES
  1. Jeanty P, Romero R, Kepple D et.al. Prenatal diagnosis in unilateral empty renal fossa. J Ultrasound Med 1990;9:651-654.
  2. Benitez CM, Cyr DR, Mack LA. Crossed fused renal ectopia: a sonographic diagnosis. J Diagn Med Sono 1985;1:218-220.
  3. Hill LM, Peterson CS. Antenatal diagnosis of fetal pelvic kidneys. J Ultrasound Med 1987;6:393.
  4. B. Atiyeh, D. Husmann and M. Baum, Contralateral renal abnormalities in patients with renal agenesis and noncystic renal dysplasia. Pediatrics 91 (1993), pp. 812–815.