Beware of the umbilical cord 'cyst'

Umbilical cord cysts: Classification, diagnosis, prognosis, and pregnancy recommendations

Umbilical cord cysts (UCCs)-cysts located in the umbilical cord that are derived from an abnormal embryonic development process-are typically an incidental discovery during prenatal ultrasound. It can be described as either a pseudocyst or a true UCC, which results from focal edema or degeneration of Wharton jelly or the remnants of embryonic development, respectively. Due to the relative rarity of the UCC, the clinical guidance of UCCs is not yet available. Herein, the aim of this paper is to discuss the classification, diagnosis, prognosis, and clinical management of UCCs through a literature review, in order to improve the understanding of UCCs among clinical obstetricians and pediatricians.

A Retrospective Cohort Analysis of the Genetic Assay Results of Foetuses with Isolated and Nonisolated Umbilical Cord Cyst

Objective

To analyse the risk of clinical chromosomal abnormalities in foetuses with umbilical cord cysts.

Methods

Data from all genetic assays that were performed as part of invasive prenatal diagnoses of umbilical cord cysts between October 2014 and June 2021 were retrospectively collected from Guangdong Women and Children Hospital. We compared the differences in genetic assay findings in isolated and nonisolated umbilical cord cyst cohorts.

Results

A total of 49 singleton pregnancies and 2 foetuses that were one of the cotwins in monochorionic twin pregnancies were enrolled in the cohort; 20 isolated and 31 nonisolated umbilical cord cysts were identified in the cohort. One foetus (5%, 1/20) in the isolated umbilical cord cyst group showed chromosomal abnormalities and 17p12 microduplication. Twelve cases (38.7%, 12/31) of chromosomal abnormalities, including seven cases of trisomy 18, two cases of trisomy 13 and three cases of microdeletion, were identified in the nonisolated umbilical cord cyst group. The incidences of chromosomal abnormalities between the two groups were significantly different (1/20, 5% vs 13/31, 38.7%, p=0.003). There was no relative pathological medical exome sequencing finding in the three foetuses suffering from nonisolated umbilical cord cysts whose parents chose to undergo chromosomal microarray analysis (CMA) and medical exome sequencing.

Conclusion

This retrospective cohort study evaluated the value of CMA in foetuses with umbilical cord cysts and suggested that copy number variants (CNVs) may be the basic genetic aetiological factors that should be considered for diagnostic evaluation. We recommended CMA as a basic genetic evaluation in cases of umbilical cord cysts, especially in nonisolated cases.

Umbilical cord anomalies: antenatal ultrasound findings and postnatal correlation

Umbilical cord anomalies are rare. The differential diagnosis for a cystic structure around the umbilical cord and its insertion include pseudocyst, omphalomesenteric duct cyst, haemangioma, omphalocele or anterior abdominal wall defects. Although cord anomalies can be detected through antenatal ultrasound scans (US), very often a definitive diagnosis cannot be made. This may affect the management of the infant at birth. In cases where antenatal US was not diagnostic, current evidence supports the use of MRI to help in making an accurate diagnosis. We report two cases of umbilical cord anomalies. The first case was diagnosed in antenatal US as an omphalocele, but was found to be an allantoic cyst with hamartoma on postnatal diagnosis. The second case was not detected on antenatal US, and was diagnosed postnatally as a small omphalocele with vitellointestinal duct remnants.

Presentation of an umbilical cord cyst with a surprising jet: a case report of a patent urachus

We report a baby with an unusual true umbilical cord cyst detected at 12 weeks gestation which as the pregnancy progressed became increasingly difficult to distinguish from a pseudocyst of the umbilical cord. Concern of the possibility of cord compression/cord accident led to an elective caesarean section being performed at 35+ week’s gestation with delivery of a healthy female infant weighing 2170g. At birth the cyst ruptured and the resultant thickened elongated cord was clamped accordingly. After the cord clamp fell off at 5 days post delivery an elongated umbilical stump was left behind from which a stream of urine surprisingly jetted out from the umbilicus each time the baby cried. A patent urachus was confirmed on ultrasound and the umbilical jet of urine resolved at 4 weeks post delivery after treatment of an Escherichia coli urinary tract infection. At 11 weeks post delivery a laparoscopic excision of the urachus was successfully performed. The baby, now 18 months of age, continues to thrive without incident.

Umbilical cord cysts: evaluation with different 3-dimensional sonographic modes

OBJECTIVE

The purpose of this series was to determine whether the use of different 3-dimensional (3D) sonographic modes allows better definition of umbilical cord cysts and pseudocysts in utero.

METHODS

Two cases of umbilical cord cysts and 1 of a pseudocyst were analyzed and compared with 2-dimensional (2D), 3D, angiopower Doppler, tomographic ultrasound imaging (TUI), virtual organ computer-aided analysis (VOCAL), and automatic volume calculation (AVC) sonographic modes. All cases were followed during pregnancy. A karyotype analysis was also obtained.

RESULTS

Three-dimensional sonography, TUI, and VOCAL allowed clear visualization and evaluation of the sizes, locations, and numbers of umbilical cord cysts. A clear differentiation between a pseudocyst and the yolk sac was obtained with AVC and angiopower Doppler sonography. The 3D sonographic surface mode allowed better visualization of other accompanying fetal malformations.

CONCLUSIONS

Three-dimensional sonography allows for a more accurate diagnosis and provides a clearer visualization of malformations than 2D imaging. Cysts and pseudocysts can be defined much more accurately by using the different modes described here.

Correlação entre o achado ultra-sonográfico isolado de cisto de cordão umbilical e anomalias fetais

OBJETIVO: Correlacionar o achado ultra-sonográfico isolado de cisto de cordão umbilical com anomalias fetais, como cromossomopatias e alterações estruturais. Segundo a literatura médica, as implicações clínicas do achado ultra-sonográfico de cisto de cordão nos segundo e terceiro trimestres de gestação estão bem estabelecidas, entretanto, quando no primeiro trimestre, o significado ainda permanece controverso. MATERIAIS E MÉTODOS: Foi realizado estudo retrospectivo de gestantes da população geral, consecutivas, com fetos únicos e vivos, que apresentavam apenas o achado de cisto de cordão umbilical, num período de dez anos (1996-2006). Em todos os casos foram realizados exames ultra-sonográficos para o rastreamento de anomalias fetais após o diagnóstico de cisto de cordão. Os recém-nascidos e o cordão umbilical foram examinados após o parto para se verificar a presença de anomalias. RESULTADOS: Foram estudados nove casos que apresentavam cisto de cordão umbilical como único achado, sem outros marcadores ultra-sonográficos de anomalias fetais. Detectaram-se dois casos no primeiro trimestre de gestação e sete nos segundo e terceiro trimestres. Dois casos foram submetidos a estudo citogenético fetal, por meio de amniocentese. Nenhum recém-nascido apresentou anomalias estruturais ou aneuploidia. CONCLUSÃO: O achado ultra-sonográfico isolado de cisto de cordão umbilical não significou aumento de risco para anomalias estruturais ou aneuploidias.

Umbilical Cord Diameter at 11–14 Weeks of Gestation: Relationship to Nuchal Translucency, Ductus Venous Blood Flow and Chromosomal Defects

OBJECTIVE

To compare the umbilical cord diameter (UCD) in euploid and aneuploid fetuses at 11-14 weeks of gestation.

METHODS

In 299 fetuses at 11-14 weeks of gestation the UCD, the nuchal translucency and the a-wave of the ductus venosus were measured. Reference ranges for the UCD according to the gestational age and to the crown-rump-length (CRL) were obtained by measuring the UCD by outer-to-outer border of 244 singleton pregnancies with normal karyotype. The fetal karyotype was established by chorionic villus sampling, amniocentesis or in case of suspected chromosomal abnormalities in the newborn. Linear regression was used to determine the significance of the association between the UCD and CRL or gestational age.

RESULTS

Two hundred and ninety-nine fetuses were examined. The median fetal CRL was 64.5 mm (range 45-84) and the median gestational age was 13 (range 11-14) weeks. In the chromosomally normal group the UCD significantly increased with the CRL (r=0.620; p<0.001) and the gestational age (r=0.555; p<0.001). The regression equation for the mean UCD (y) according to the gestational days (x) was: y=-0.604+0.051*x. The regression equation for the mean UCD (y) according to the CRL (x) was: y=1.962+0.029*x. There were no significant differences in the mean UCD in fetuses without and with chromosomal abnormalities. The proportion of fetuses with an UCD above the 95th centile for CRL was higher in aneuploid compared to euploid fetuses (5/14 vs. 13/285, p<0.005). In 5/14 (35.7%) fetuses with chromosomal defects the NT and the UCD were above the 95th centile, whereas none of the fetuses with normal karyotype showed this combination. The proportion of fetuses with increased UCD and abnormal DV blood flow was increased in the cases with chromosomal abnormalities (33.3 vs. 1.8%, p<0.005).

CONCLUSION

Umbilical cord diameter at 11-14 weeks increases with fetal CRL. Fetuses with chromosomal abnormalities are more likely to have an UCD above the 95th centile. Therefore, sonographic evaluation of the umbilical cord during first trimester ultrasound might be of additional value in the assessment of fetuses at risk for aneuploidies.

Characteristics and outcome of 90 cases of fetal omphalocele

OBJECTIVE

The aim of this study was to describe the outcome of a case series of fetuses with omphalocele.

METHODS

Ninety fetuses with omphalocele at the National Center for Fetal Medicine (NCFM) between January 1985 and January 2004 were followed from the time of prenatal diagnosis. Follow-up times ranged from 6 months to 17 years. Omphaloceles were subdivided into epigastric, central and hypogastric types based on their location on the abdominal wall.

RESULTS

There were 58 central and 32 epigastric omphaloceles. Abnormal karyotype was found in 40/58 (69%) of the central and in 4/32 (12.5%) of the epigastric omphaloceles. Trisomy 18 was the most frequent abnormality associated with omphalocele. Among the fetuses with normal karyotype, 89% of the central and 71% of the epigastric cases had other anomalies. 38 (66%) of the fetuses with central omphalocele were terminated and 12 (21%) died during pregnancy or after delivery. 11 (34%) of the fetuses with epigastric omphalocele were terminated and eight (25%) died during pregnancy or after delivery. Of the 90 cases followed from the time of diagnosis there were 21 (23%) survivals. Of eight survivals with central omphalocele, only two were considered healthy while six had other anomalies and/or substantially impaired development. Of 13 survivals with epigastric omphalocele, six were considered healthy and seven had other anomalies and/or substantial impairment.

CONCLUSIONS

Fetal central and epigastric omphaloceles may be different entities: central omphaloceles are more strongly associated with abnormal karyotype (69%) than are epigastric omphaloceles (12.5%). The outcome of fetuses with omphalocele is poor irrespective of the type of omphalocele, with only eight of the 90 (9%) being alive and healthy at present. The results emphasize the importance of identifying both those fetuses with a potentially good prognosis and favorable outcome and those which are likely to have a fatal outcome.