ABSTRACT
Duplication of the ureter and renal pelvis is the most common upper urinary tract anomaly with a reported incidence of 0.8" in the population and in 1.8"-4.2" of pyelograms. The ureteric bud appears at 5 weeks' gestation from the place where the Wolffian duct bends centrally and medially to the cloaca and pushes into the pelvic metanephrogenic mass and eventually forms the ureter and renal pelvis. Most often, ureteral duplication anomalies are discovered incidentally unassociated with any symptoms. Infants may come to medical attention because of the complications of obstruction of the upper moiety or infection. Ureterocele, a cystic dilatation of the terminal intramural segment of the distal ureter, is classified as either simple or ectopic. The kidneys can be imaged at the 12th gestational week by abdominal ultrasound. With the increased availability and use of maternal ultrasonography, the incidence of urinary tract disorders diagnosed in utero has increased considerably.
