Prenatal diagnosis of cystic bladder distension secondary to obstructive uropathy

We report the perinatal findings of a huge midline posterior cystic bladder distension secondary to lower urinary tract obstruction and prune-belly syndrome in a male fetus. A 40-year-old woman, gravida 3, para 0, was referred at 21 gestation weeks with sonographic findings of anhydramnios and a fetus with a 9.5 x 6.0 cm intra-abdominal cystic mass containing two chambers. The in utero ultrasound-guided fetal bladder drainage using a single needle aspiration and the ultrasound follow-ups of fetal bladder filling provided a diagnostic aid. This method helped to show the position of the bladder and the cystic bladder mass as well as the status of communication in response to decompression or filling of the fetal bladder. Cytogenetic analysis revealed a 46,XY karyotype. Autopsy showed agenesis of the posterior urethra, prominent megacystis, a cystically distended mass arising from the lower posterior bladder, hydronephrosis, megaureters, and anorectal agenesis with an intestinal blind end adherent to the posterior wall of the uterus. There were no urogenital duplication, hindgut duplication, or urachal abnormalities. The contracted bladder had a full-thickness muscular wall with a trigone and two ureteral orifices while the cystically distended bladder did not have any opening and was lined by a very thin wall. Histology of the cystic bladder wall demonstrated typical urothelium, lamina propria and muscularis propria. The pathogenesis and differential diagnosis of cystic bladder distension are discussed.