Fetal enteric duplication cysts are enteric duplication cysts presenting in utero.

Epidemiology

Associations

They are associated with additional abnormalities in up to a third of the cases. These are most commonly vertebral anomalies ³.

Pathology

They result from an abnormal recanalization of the gastrointestinal tract. They comprise of a two-layer smooth muscle wall and an internal epithelium of a respiratory or intestinal type. These cysts may or may not communicate with the lumen of the gastrointestinal tract. They can be cystic or tubular (with the latter more likely to communicate with the gastrointestinal tract). 

Location

They can occur anywhere along the gastrointestinal tract although a greater predilection towards the ileal region (~40%) ³.

Radiographic features

Ultrasound

Usually seen as an anechoic cystic lesion within the abdomen that is separate from normal hollow structures such as the bladder and stomach. 

Relatively characteristic signs that have been described include ¹:

• double wall sign: may not always be present

• gut signature sign: may not always be present

Occasionally they can also present as an echogenic mass ³  (probably due to hemorrhage).

If there is a complicating bowel obstruction, there may be evidence of polyhydramnios.

Treatment and prognosis 

Recognized complications include:

• in utero bowel obstruction, sometimes with associated perforation

Differential diagnosis

Considerations on ultrasound for an anechoic mass include:

• fetal omental cyst

• fetal mesenteric cyst

• meconium pseudocyst

• fetal ovarian cyst

See also

• fetal intra-abdominal cystic lesions