omphalomesenteric duct cyst
An omphalomesenteric duct cyst is a type of true umbilical cord cyst.
Pathology
The omphalomesenteric duct serves as a communication between the midgut and yolk sac In early embryonic life and usually obliterates between the 9-18week of gestation. The omphalomesenteric duct cyst is an embryologic remnant of the yolk stalk. If the yolk stalk does not obliterate completely, various portions may persist giving rise to many entities including an omphalomesenteric duct cyst. The cysts are lined by a columnar mucin-secreting epithelium. Eventually, these cysts may contain gastric, colonic, pancreatic and/or small intestinal epithelium.
Radiographic features
Antenatal ultrasound
They may be seen as a cystic mass towards the fetal end of the umbilical cord as
well as being located close to the periphery of the cord (c.f. allantoic cysts which are central). Color Doppler interrogation show no vascularity (c.f. umbilical arterial aneurysm).
Differential diagnosis
- allantoic cyst: located centrally in the cord
- umbilical arterial aneurysm: show Doppler signal