Radiology, Vol 182, 719-722, Copyright © 1992 by Radiological Society of North America
First-trimester umbilical cord cysts
LK Skibo, EA Lyons and CS Levi
Department of Radiology, Health Sciences Centre, Winnipeg, Man, Canada.
Cystic masses of the umbilical cord have been detected in the 2nd and 3rd
trimesters of pregnancy in association with fetal abdominal wall defects
and chromosomal anomalies. With high-resolution endovaginal ultrasound
(US), umbilical cord cysts can be visualized during the 1st trimester.
Their origin and significance must be considered for proper obstetric
management. The authors report eight cases in which cystic masses of the
umbilical cord were detected during US examinations performed at 8-9 weeks
menstrual age. In the five cases followed to term, both the infant and the
umbilical cord were found to be normal at physical examination.
Sonographically, all cysts appeared to be eccentric in relation to the
umbilical cord, and, although all were closer to the fetus, the cysts were
clearly extraembryonic. Cyst size was 2.0-7.5 mm (mean, 5.2 mm). Seven
cysts resolved by 12 weeks menstrual age. The incidence of cysts in
patients who underwent US at the authors' institution between 8 and 12
weeks menstrual age was 0.4%; the true frequency is unknown without routine
1st-trimester scanning of all patients.
