Duplicated ureter

A ureteric bud, arising from the mesonephric (or Wolffian) duct, gives rise to the ureter, as well as other parts of the collective system.

In most cases, the kidney is divided into two parts, an upper and lower lobe, with some overlap due to intermingling of collecting tubules.

However, in some cases the division is so complete as to give rise to two separate parts, each with its own renal pelvis and ureter.

[citation needed] Prenatally diagnosed hydronephrosis (fluid-filled kidneys) suggest post-natal follow-up examination.

A hydronephrotic kidney may present as a palpable abdominal mass in the newborn, and may suggest an ectopic ureter or ureterocele.