Pediatric Orthotopic Ureterocele

  • Etiology: Congenital dilation of distal most ureter that prolapses into bladder
  • Imaging: Occurs at normal ureterovesical junction
  • Imaging US: Cystic structure projecting into bladder near the ureterovesical junction that is hard to see after endoscopic puncture
  • Imaging VCUG: Round lucency or filling defect near trigone of bladder during early filling phase that may efface with increased bladder filling
  • DDX: Bladder diverticulum
  • Complications: Ureteral obstruction, vesicoureteral reflux, bladder outlet obstruction
  • Treatment: Cystoscopic puncture or surgical excision
  • Clinical:
    — Less common than ectopic ureterocele
    — Usually seen in adolescents and adults

Radiology Cases of Orthotopic Ureterocele

CT and VCUG of bilateral orthotopic ureteroceles
Coronal (above left) and axial (below left) CT without contrast of the abdomen show single renal collecting systems bilaterally along with bilateral oval fluid-filled structures superior and posterior to the bladder near the ureterovesical junctions. AP image from a voiding cystourethrogram exam (right) shows two large round filling defects in the bladder.

US and MAG3 nuclear medicine scan of orthotopic ureterocele
Transverse US of the bladder (above left) shows a round cystic lesion in the base of the bladder. Sagittal US of the bladder (above right) shows to the left of the image an extremely dilated left ureter and to the right of the image again the round cystic lesion in the base of the bladder. Sagittal image of the left renal fossa (below left) shows non-visualization of the left kidney. Nuclear medicine MAG3 scan (below right) shows a normal right kidney, non-visualization of the left kidney, and a round photopenic defect in the bladder.

US and VCUG of pediatric everting orthotopic ureterocele
Transverse ultrasound of the bladder (above left) shows an oval lesion in the center of the bladder that has a thick wall and a hypoechoic center. AP image early in the filling phase of a voiding cystourethrogram exam (above right) shows an oval lucent filling defect representing a lesion in the center of the bladder. AP image from later in the filling phase (below left) shows the filling defect / lesion is within the bladder. Lateral image from the voiding phase (below right) shows the lesion has everted out of the bladder. Left sided vesicoureteral reflux was also present.