Congenital and Acquired Genitourinary Anomalies
Core concepts
Master the embryology of the ureteric bud and metanephric blastema to explain duplication, ectopic ureter, ureterocele, and multicystic dysplastic kidney. Understand antenatal hydronephrosis grading (SFU/UTD), vesicoureteral reflux grading (I-V), and when to observe versus intervene. Posterior urethral valves are the classic cause of bilateral hydronephrosis in a male neonate; anterior urethral valves are rare. Hypospadias: know meatal location, chordee, and the contraindication to circumcision before repair. Undescended testis: timing of orchidopexy (6-18 months), risks of malignancy and infertility, and the difference between retractile and true cryptorchidism. Other anomalies: prune-belly syndrome, epispadias/exstrophy, horseshoe kidney, UPJ obstruction, and ureterovesical junction obstruction. Recognize acquired anomalies such as urethral stricture and bladder diverticula.
Traps
- Calling a retractile testis undescended; retractile testes do not need surgery.
- Missing a ureterocele as the cause of a duplicated system with upper pole obstruction.
- Assuming all antenatal hydronephrosis needs surgery; most resolve.
- Forgetting that circumcision is deferred in hypospadias to preserve skin for reconstruction.
Worked example
A neonate with bilateral hydronephrosis and a thick-walled bladder in a male should be evaluated for posterior urethral valves with voiding cystourethrogram; catheter drainage and valve ablation follow.
Rule of thumb
Laterality and level of dilation tell the story: unilateral hydronephrosis suggests UPJ or UVJ obstruction, while bilateral suggests valves or bladder dysfunction.