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Ectopic ureterocele

Published:September 07, 2021DOI:https://doi.org/10.1016/j.ajog.2021.06.041

      Introduction

      An ectopic ureterocele is commonly associated with the ectopically inserted ureter of a duplicated collecting system and is more common in female fetuses.
      • Kang A.H.
      • Bruner J.P.
      Antenatal ultrasonographic development of ureteroceles. Implications for management.
      ,
      • Shokeir A.A.
      • Nijman R.J.
      Ureterocele: an ongoing challenge in infancy and childhood.
      It can be detected on prenatal imaging as an incidental finding or during the evaluation of hydronephrosis.

      Definition

      A ureterocele is a cystic dilation of the terminal ureter. The American Academy of Pediatrics classifies ureteroceles based on their location. Intravesical ureteroceles are located entirely in the bladder and are more common in adults than in fetuses and children.
      • Coplen D.E.
      • Duckett J.W.
      The modern approach to ureteroceles.
      Ectopic ureteroceles are located distal to the trigone, inserting into the bladder neck, urethra (cecoureterocele), or elsewhere in the pelvis, and are more likely to be detected during prenatal or pediatric imaging.
      • Glassberg K.I.
      • Braren V.
      • Duckett J.W.
      • et al.
      Suggested terminology for duplex systems, ectopic ureters and ureteroceles.
      Approximately 80% of ureteroceles are associated with the upper pole of a duplicated collecting system; moreover, 60% of these are ectopic.
      • Coplen D.E.
      • Duckett J.W.
      The modern approach to ureteroceles.
      ,
      • Athey P.A.
      • Carpenter R.J.
      • Hadlock F.P.
      • Hedrick T.D.
      Ultrasonic demonstration of ectopic ureterocele.

      Ultrasound Findings

      On ultrasound, a ureterocele appears as a thin-walled cystic mass seen in the fetal bladder. It is best visualized when the bladder is partially filled. A ureterocele can be confused with the bladder when the bladder is completely empty. Conversely, the ureterocele can become compressed or prolapse if the bladder is completely full.
      • Garmel S.H.
      • Crombleholme T.M.
      • Cendron M.
      • Klauber G.
      • D’Alton M.E.
      The vanishing fetal ureterocele: a cause for concern?.
      Therefore, the bladder should be visualized more than once throughout the ultrasound examination.
      When an ectopic ureterocele is suspected, the bladder, bilateral kidneys, bilateral ureters, and amniotic fluid should be carefully evaluated. The fetal kidneys should be visualized both axially and longitudinally. Obstruction of the ureter by the ureterocele at the ureterovesical junction can lead to a dilated ureter and hydronephrosis. Renal duplication is often associated with the visualization of two separate renal poles, with the ectopic ureter most commonly draining the upper renal pole moiety.
      • Queiroga Jr., E.E.
      • Martins M.G.
      • Rios L.T.
      • et al.
      Antenatal diagnosis of renal duplication by ultrasonography: report on four cases at a referral center.
      Obstruction from the ureterocele is often seen in the upper pole moiety. In addition, the lower renal pole moiety can be dilated, generally from reflux. The duplicated kidney may be larger than the contralateral kidney. The lower pole moiety may also be displaced inferiorly because of mass effect.
      If a ureterocele is sufficiently large, it can lead to obstruction of the contralateral kidney or bladder outlet obstruction, resulting in oligohydramnios.

      Associated Abnormalities

      Ureteroceles are generally isolated anomalies and are not associated with anomalies outside of the urologic system. The contralateral kidney and ureter should be visualized carefully to assess for contralateral duplication.

      Differential Diagnosis

      When a cystic mass is seen in the fetal bladder, it most commonly represents an ectopic ureterocele. The kidneys should be carefully examined to look for a duplicated collecting system. The differential diagnoses of ectopic ureterocele include anomalies associated with hydronephrosis, such as posterior urethral valves, ureteropelvic junction obstruction, vesicoureteral reflux, and congenital megaureter. However, in these conditions, the bladder appears normal. A bladder “hutch” diverticulum, or periureteral bladder diverticulum, can have a similar appearance to that of a ureterocele, but it is extrinsic and does not prolapse into the bladder lumen. The visualization of a crescentic membrane in the fetal bladder is considered pathognomonic for ectopic ureterocele (Figure).
      Figure thumbnail gr1
      FigureAxial and longitudinal views of the bladder
      Axial (A) and longitudinal (B) views of the bladder showing a ureterocele (marked with asterisk).
      B, bladder.
      Society for Maternal-Fetal Medicine. SMFM Fetal Anomalies Consult Series #4. Am J Obstet Gynecol 2021.

      Genetic Evaluation

      An ectopic ureterocele is generally considered a sporadic finding. In the absence of other anomalies or a concerning family history, genetic evaluation beyond routine aneuploidy screening is not generally recommended.

      Pregnancy and Delivery Management

      Follow-up ultrasound examination is recommended to follow fetal growth, measure amniotic fluid volume, and assess for development of renal obstruction. In utero decompression with laser incision or needle puncture has been described in cases of ectopic ureterocele with bladder outlet obstruction and oligohydramnios
      • Chalouhi G.E.
      • Morency A.M.
      • De Vlieger R.
      • et al.
      Prenatal incision of ureterocele causing bladder outlet obstruction: a multicenter case series.
      and may be considered in specialty centers under a research protocol. Prenatal pediatric urology and neonatology consultations should be considered to provide counseling about prognosis and postnatal management. Obstetrical management, delivery timing, and mode of delivery should be based on obstetrical indications.

      Prognosis

      The prognosis of ectopic ureterocele is largely dependent on the degree of renal obstruction. The prognosis is excellent in the absence of obstruction or reflux.
      • Shankar K.R.
      • Vishwanath N.
      • Rickwood A.M.
      Outcome of patients with prenatally detected duplex system ureterocele; natural history of those managed expectantly.
      ,
      • Rickwood A.M.
      • Reiner I.
      • Jones M.
      • Pournaras C.
      Current management of duplex-system ureteroceles: experience with 41 patients.
      If not detected antenatally, ectopic ureterocele may present as a urinary tract infection in the first months of infancy
      • Coplen D.E.
      • Duckett J.W.
      The modern approach to ureteroceles.
      and can lead to urosepsis. The prognosis is improved with prenatal diagnosis and earlier initial intervention when indicated. In one retrospective study of 95 patients with prenatal or postnatal diagnosis, the incidence of urinary tract infection was decreased with prenatal diagnosis, as was the need for secondary procedures (20% vs 46%).
      • Upadhyay J.
      • Bolduc S.
      • Braga L.
      • et al.
      Impact of prenatal diagnosis on the morbidity associated with ureterocele management.
      The postnatal workup generally includes an ultrasound examination of the bladder and kidneys and a voiding cystourethrogram. A radionucleotide renal scan can help assess kidney function. Pediatric urology consultation is recommended. Surgery can be considered, especially in the case of vesicoureteral reflux.
      • Shankar K.R.
      • Vishwanath N.
      • Rickwood A.M.
      Outcome of patients with prenatally detected duplex system ureterocele; natural history of those managed expectantly.
      ,
      • Rickwood A.M.
      • Reiner I.
      • Jones M.
      • Pournaras C.
      Current management of duplex-system ureteroceles: experience with 41 patients.
      Surgical options include endoscopic ureterocele decompression, heminephrectomy, bladder reconstruction, and ureteral reimplantation.

      Summary

      An ectopic ureterocele appears ultrasonographically as a thin-walled cystic mass seen in the fetal bladder and represents a cystic dilation of the terminal ureter. It is most commonly associated with a duplicated collecting system and can lead to varying degrees of renal obstruction. Serial follow-up ultrasound examinations are recommended to assess fetal growth, amniotic fluid volume, and progression of renal obstruction. The prognosis of ectopic ureterocele is largely dependent on the degree of renal obstruction and can be excellent in the absence of obstruction or reflux. Prenatal pediatric urology and neonatology consultations should be considered, and postnatal pediatric urology consultation is recommended. Postnatal urologic surgery may be necessary, especially in cases of severe obstruction or reflux.

      References

        • Kang A.H.
        • Bruner J.P.
        Antenatal ultrasonographic development of ureteroceles. Implications for management.
        Fetal Diagn Ther. 1998; 13: 157-161
        • Shokeir A.A.
        • Nijman R.J.
        Ureterocele: an ongoing challenge in infancy and childhood.
        BJU Int. 2002; 90: 777-783
        • Coplen D.E.
        • Duckett J.W.
        The modern approach to ureteroceles.
        J Urol. 1995; 153: 166-171
        • Glassberg K.I.
        • Braren V.
        • Duckett J.W.
        • et al.
        Suggested terminology for duplex systems, ectopic ureters and ureteroceles.
        J Urol. 1984; 132: 1153-1154
        • Athey P.A.
        • Carpenter R.J.
        • Hadlock F.P.
        • Hedrick T.D.
        Ultrasonic demonstration of ectopic ureterocele.
        Pediatrics. 1983; 71: 568-571
        • Garmel S.H.
        • Crombleholme T.M.
        • Cendron M.
        • Klauber G.
        • D’Alton M.E.
        The vanishing fetal ureterocele: a cause for concern?.
        Prenat Diagn. 1996; 16: 354-356
        • Queiroga Jr., E.E.
        • Martins M.G.
        • Rios L.T.
        • et al.
        Antenatal diagnosis of renal duplication by ultrasonography: report on four cases at a referral center.
        Urol J. 2014; 10: 1142-1146
        • Chalouhi G.E.
        • Morency A.M.
        • De Vlieger R.
        • et al.
        Prenatal incision of ureterocele causing bladder outlet obstruction: a multicenter case series.
        Prenat Diagn. 2017; 37: 968-974
        • Shankar K.R.
        • Vishwanath N.
        • Rickwood A.M.
        Outcome of patients with prenatally detected duplex system ureterocele; natural history of those managed expectantly.
        J Urol. 2001; 165: 1226-1228
        • Rickwood A.M.
        • Reiner I.
        • Jones M.
        • Pournaras C.
        Current management of duplex-system ureteroceles: experience with 41 patients.
        Br J Urol. 1992; 70: 196-200
        • Upadhyay J.
        • Bolduc S.
        • Braga L.
        • et al.
        Impact of prenatal diagnosis on the morbidity associated with ureterocele management.
        J Urol. 2002; 167: 2560-2565