False-positive WBC imaging secondary to a distended bladder and fecal retention

We present the sonographic findings of a fetus with a vesicoallantoic cyst. The cyst was first identified at 17 weeks of gestation; it was associated with an omphalocele, and disappeared spontaneously at 29 weeks. The fetal urinary bladder was not visualized thereafter. An omphalocele and exstrophia of the urachus were found at birth and repaired. Non-visualization of the fetal urinary bladder suggested rupture of the covering membrane of the omphalocele and allantois during fetal life. A defect in the wall of the omphalocele supported our hypothesis.