Ureterocele

Clinical                      A ureterocele is a congenital anomaly consisting of a dilated intramural ureteral segment. It is associated with urinary retention and infection. Ureteroceles are mostly a pediatric diagnosis but they occasionally first manifest in adulthood.
They are classified into simple and ectopic, depending on the distal orifice. About 10% are bilateral. Some authors suggest that siblings of children with ureteroceles be screened for urogenital abnormalities.
Ectopic ureteroceles are often part of a duplicated renal collecting systems,with most terminating a ureter draining the upper renal pole. They are more common in girls and are a common cause of bladder obstruction in girls.
An extreme example consists of bilateral ureteroceles and bilateral duplex systems. An ectopic ureterocele does occur in patients with a single kidney or a horseshoe kidney. An ectopic ureterocele can distort an adjacent normally located ureterovesical junction to the point of inducing reflux. A rare ureterocele prolapses
and even strangulates. Or occasionally a simple ureterocele even prolapses into the urethra and leads to bladder outlet obstruction.
Bladder outlet obstruction can also be due to a simple ureterocele if it is large enough. If necessary, a ureterocele is treated by endoscopic ureterocele incision; the success rate is lower with ectopic ureteroceles. Vesicoureteral reflux develops after such endoscopic incision in about half the patients, with reflux being more common with an ectopic ureterocele.
Imaging Intravenous urography of a simple ureterocele is usually diagnostic. A ureterocele is seen as a cyst-like dilation of the distal ureter protruding into the bladder lumen; the ureterocele wall appears as a thin radiolucent line, although infection or stasis results in thickening. The typical “cobra-head” appearance is familiar to most radiologists. At times urography simply reveals a large radiolucent tumor in the bladder in association with nonvisualization of the ipsilateral kidney upper pole. A cystogram detects a ureterocele, provided instilled contrast does not efface or obscure it. Serial visualization during bladder filling and voiding is helpful.
image
This is radiology images of ureterocele. Excretory phase three-dimensional (3D) computed tomography (CT) reconstruction identifies hydronephrosis, hydroureter, and a ureterocele (arrow).

Computed tomography of a ureterocele reveals a well-marginated soft tissue tumor at the ureteral insertion. A simple ureterocele is seen on US as a thin-walled, fluid-filled structure at the trigone. Occasionally a diminutive renal upper pole is drained by a small duplicated ureter that terminates in a relatively large ureterocele. This condition, called ureterocele disproportion, is difficult to diagnose with most imaging modalities.
Some ureteral duplications and ectopic ureteroceles are associated with ureteral obstruction, marked hydronephrosis, and dilation of the involved ureter to the point that adjacent nonobstructed collecting systems are displaced inferiorly. The reverse can also occur—occasionally an obstructed normal ureter mimics the appearance of a ureterocele.
Stones develop in some ureteroceles. The term ureterocele eversion describes a ureterocele that everts or intussuscepts retrograde into the ureter during voiding cystourethrography. Radiographically, the outpouching can appear similar to a paraureteral bladder diverticulum.At times fluoroscopy aids in detecting these eversions.
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