PMC8476282_01
Allantoic cyst during ultrasound examination at the 13th week of gestation. Note its position within the umbilical cord and adjacent to the abdominal wall. It is avascular, in communication with the bladder and embraced by the two umbilical arteries.
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Its size varied during the ultrasound examination, which lasted several hours, configuring the diagnostic suspicion of an allantoic cyst with patent urachus (Figure 1).
Same allantoic cyst during the second trimester scan examination at the 22nd week of gestation. Appreciate the increased size and the communication with the bladder.
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The biometric values appeared overall greater than a week compared to gestational age, and the allantoic cyst showed an increased size, with a maximum diameter of 46 mm; the remaining anatomy explored by ultrasound was regular (Figure 2).
In the ultrasound examination performed at the 32nd week of gestation, the allantoic cyst was no longer visible and replaced by an omphalocele of 35 x 31 millimeters, secondary to the cyst's rupture.
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In the following ultrasound check, performed during the 32nd week of gestation, the cyst and the bladder were no longer visible, due to cyst rupture, while an omphalocele of 35 x 31 millimeters appeared, consisting of loops of small intestines coated with membranes (Figure 3).
Postnatal confirmation of omphalocele which needed urgent surgical correction because of spontaneous rupture of the peritoneum.
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Two days after birth, the peritoneum covering intestinal loops broke spontaneously, and the newborn underwent successful urgent surgery (Figure 4).