Bladder prolapse through a patent urachus presenting as an umbilical mass in the newborn: characteristic prenatal sonographic findings and the diagnostic benefit of postnatal cystography

Prenatal Detection of Vesico-Allantoic Cyst: Ultrasound and Autopsy Findings

Introduction: The vesico-allantoic cyst is a communication between the fetal bladder and the allantois through a patent urachus.Case Report: We describe a 17-week of gestational age (WGA) fetus with a 40 x 30 mm vesico-allantoic cyst. At 19 WGA, ultrasound (US) detected bilateral dilatation of renal pelvis (5-6 mm), hydroureters, and hypospadias. Amniotic fluid, umbilical cord flow, and fetal biometry were regular. Due to uncertain prognosis, the parents opted for legal termination of pregnancy. Autopsy confirmed the prenatal findings, also revealing intestinal malrotation and Meckel's diverticulum.Discussion/Conclusion: Probably an initial urinary tract obstruction occurred, not yet affecting the amniotic fluid volume, but evident as pyelectasis. This case highlights the possibility that genito-urinary and intestinal anomalies may be found in association with the vesico-allantoic cyst.