What Are Umbilical Cysts?

Umbilical cord cysts ^[1] are cysts that occur in the umbilical cord and originate from the remaining parts of the umbilical ureter and yolk duct. Most umbilical cord cysts are sporadic and can also occur in trisomy 18 and other chromosomal aberrations. Umbilical cord cysts are also associated with non-chromosomal abnormalities. ^[1]

Umbilical cord cyst

Umbilical cord cyst ^[1]

Umbilical cord cysts can be divided into true cysts and pseudocysts.

The wall of a true cyst has a layer of epithelial cells, including the umbilical mesenteric tube or allantoic tube. Amniotic cysts have a layer of amniotic epithelium. Umbilical mesenteric or allantoic cysts occur in the fetal end of the umbilical cord, and are often associated with gastrointestinal and urogenital tract malformations, which may be related to their embryonic development. In particular, allantoic cysts are often associated with umbilical bulge, Open umbilical catheter.

Pseudocysts are not covered by epithelium. Due to the local edema or local degeneration of Huateng gum that surrounds the umbilical cord, it is more common than true cysts. It is reported in the literature that it is related to umbilical bulge and trisomy 18.

1. Circular non-echo nodules can be seen inside the umbilical cord, the capsule is complete, and the internal sound transmission is good.

Umbilical cysts in the second and third trimesters are related to fetal malformations and aneuploidies. Studies have shown that umbilical cord cysts are present in up to 50% of cases. Therefore, fetal chromosome examination should be performed if umbilical cysts are found in the second and third trimesters of pregnancy. However, in early pregnancy, umbilical cord cysts are likely to be a normal phenomenon, most of which can go away on their own and persist throughout the pregnancy. Some studies have found that the incidence of fetal malformations in patients with persistent cysts is significantly higher than those with early disappearance of cysts. In addition, when the cyst is located at the fetal end of the umbilical cord or the placental end, that is, the position of the cyst is eccentrically distributed with respect to the long axis of the umbilical cord, the risk of fetal malformation is also significantly increased.

[1]. Li Hui, Li Shengli, and Song Wenling, the chief translator of Atlas of Fetal Anomaly Diagnosis [2]. Li Shengli, the editor of Prenatal Ultrasound Diagnosis of Fetal Malformations