Most ureteroceles are associated with a duplex system (two ureters draining the kidney). Often there is little or no function to the upper segment of kidney. Fortunately this upper segment represents a very small portion of the overall kidney. Histologic or pathologic analysis of these upper pole segments usually demonstrates varying degrees of renal dysfunction which may be one justification for removal of these segments. The most common reason for their removal is the combination of non-function and obstruction.

Ureteroceles can cause significant anatomic distortion to other surrounding structures such as the ureteral orifice of the other kidney (contralateral), the trigone and the bladder neck. This may result in contralateral vesicoureteral reflux due to distortion of the bladder or cause contralateral reflux due to obstruction by the ureterocele at the bladder neck. Certain types of ureteroceles such as the cecoureterocele (a ureterocele that extends beyond the bladder sphincter) can cause incontinence (wetting) by interference with the normal continence mechanism due to the submucosal extension of the ureterocele sac. Less frequent presentations of ureterocele include hematuria, failure to thrive, abdominal pain, or pelvic pain.

In infants and children, the normal ureter is not visualized by ultrasound. The identification of a ureter by ultrasound indicates an abnormal finding necessitating full evaluation. Dilatation of the ureter is usually secondary to reflux or obstruction. Among patients with ureteroceles involving a duplex system (two ureters draining one kidney), the renal ultrasound usually shows a dilated upper pole segment with little renal cortex. On occasion, there may be near normal appearing renal cortex associated with the dilated upper pole segment. In single system ureteroceles, the kidneys often appear normal or may demonstrate mild hydronephrosis. In our experience, abnormalities of the renal echotexture are unusual with single system ureteroceles.

Identification of the ureterocele during the bladder ultrasound can be challenging. If the bladder is empty, the ureterocele wall may be touching the bladder wall making the distinction between the two impossible. In this instance, the entire ureterocele may be mistaken for the bladder. Trained pediatric radiologists aware of this phenomenon can generally avoid this misinterpretation. Passage of a feeding tube and partial filling of the bladder will also help clarify the anatomy. At the other extreme, bladder filling can cause compression or collapse of the ureterocele. In this instance, the bladder is visualized but the ureterocele is not seen. Further filling of the bladder may cause the extravesical prolapse of the ureterocele due to the lack of bladder wall backing. In this instance, the prolapsed or everted ureterocele may be mistaken for a bladder diverticulum. Partial bladder decompression and reimaging will help to avoid this misinterpretation. The best images are obtained when the bladder is partially filled allowing the dilated ureterocele to be surrounded by bladder urine and causing separation of ureterocele wall from the bladder wall.

Additional studies may also be necessary to help