A Case of Patent Urachas with Fetal MRI and Ultrasonography Showing Giant Umbilical Cord Cysts

Abstract

An umbilical cord cyst is a congenital anomaly that is associated with a urachal patent and chromosomal abnormalities. We report a case of a neonate diagnosed with urachal patent after the identification of an umbilical cord cyst by fetal ultrasonography and MRI. Prenatal ultrasonography at 29 weeks of gestation revealed an umbilical cord cyst. The cyst became enlarged and the umbilical cord became edematous. At 36 weeks of gestation, fetal MRI revealed a connection between the bladder and the umbilical region. The infant was delivered by scheduled cesarean section at 38 weeks and 3 days of gestation. The umbilical cord on the fetal side showed edematous changes for approximately 30 cm, and a yellowish transparent cyst measuring 6 × 4 × 4 cm was identified about 5 mm from the infant side. On day 5 after birth, cystography showed a urachal patent. Urachal resection was performed on postnatal day 7. The postoperative course was uneventful. This case highlights the importance of considering the possibility of a urachal patent when an umbilical cord cyst is identified during the fetal period. Early diagnostic examinations such as cystography should be performed after birth.