The non-obstructive ectopic ureterocele.

We have seen 5 children with a non-obstructive ectopic ureterocele associated with an undilated upper pole collecting system. Thus the telltale signs of renal duplication found with obstruction of the upper pole were absent. Cystoscopy confirmed the diagnosis when retrograde injection of the ureterocele outlined a narrow ureter and small dysplastic kidney. Because reflux usually was present in the ipsilateral lower pole ureter (86 per cent) surgical treatment consisted of excision of the ureterocele and common sheath ureteral reimplantation. Removal of the small non-functioning upper renal segment was not necessary in most instances. The embryology of this anomaly is discussed.