title: Single-system ureteroceles in infants and children: imaging features.
abstract: OBJECTIVE
  The purpose of this manuscript is to describe the clinical and imaging findings in children who have single-system ureteroceles.
  
  
  METHODS
  We reviewed the urology records and imaging studies in 32 consecutive infants and children who were diagnosed in our department with single-system ureteroceles.
  
  
  RESULTS
  There were 35 ureteroceles in the 32 patients-- 29 were unilateral (14 right-sided, 15 left-sided) and 3 were bilateral. Twenty-five patients were boys (78 %) and 7 girls. Mean age at presentation was 0.7 years (0-9.2 years). Prenatally detected hydronephrosis or cystic renal dysplasia was the most common presentation (24 patients). Four presented with urinary infection, 2 with abdominal mass, 1 had myelomeningocele, and 1 had hypospadias. Three patients also had multiple non-urologic, congenital anomalies. Thirty-three ureteroceles were intravesical, and 2 were ectopic to the bladder neck. Twenty-four ureteroceles were associated with ipsilateral hydroureteronephrosis and 10 with ipsilateral multicystic dysplastic kidney. One patient had a normal ipsilateral kidney and a contralateral multicystic dysplastic kidney. The ureterocele was identified on at least one imaging study in each patient. Sixteen ureteroceles (47%) everted at VCUG, mimicking paraureteral diverticula. Other variations included ureterocele prolapse and inadvertent ureterocele catheterization (1 each).
  
  
  CONCLUSIONS
  Single-system ureterocele is an important, although uncommon cause of hydronephrosis and renal dysplasia in infants and children. Single-system ureterocele is distinguished clinically from the more common duplex-system ureterocele by its frequent occurrence in boys and its association with multicystic dysplastic kidney. Because these ureteroceles are frequently small and have a propensity to evert at VCUG, they can be mistaken for paraureteral diverticula.
authors.affiliation: Department of Radiology, Indiana University Medical Center, James Whitcomb Riley Hospital for Children, Indianapolis 46202-5200, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Zerin
authors.forename: D R
authors.initials: DR
authors.lastname: Baker
authors.forename: J A
authors.initials: JA
authors.lastname: Casale
mesh_terms: D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006869:Hydronephrosis / Q000209:etiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D007690:Polycystic Kidney Diseases / Q000209:etiology; D012189:Retrospective Studies; D014463:Ultrasonography; D014518:Ureterocele / Q000145:classification / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D014551:Urinary Tract / Q000002:abnormalities