Cystic anomalies of biliary tree in the fetus: is it possible to make a more specific prenatal diagnosis?
OBJECTIVE
Biliary tree cystic malformations (BCM) occur rarely. Current progress in ultrasonography makes it possible to identify them prenatally. The aim of this study was to analyze retrospectively prenatal ultrasound patterns of 5 consecutive subhepatic cysts in an effort to differentiate the BCM before birth and onset of symptoms.


METHODS
The prenatal ultrasound patterns of 5 consecutive BCM were correlated with the postnatal diagnosis.


RESULTS
Case 1 showed a hyperechogenic cyst that underwent enlargement during fetal life; the diagnosis at birth was an obstructed choledochal cyst (CC). In cases 2 and 3, an anechoic cyst with small, stable dimensions during pregnancy was identified; a biliary atresia (BA) type III-C was confirmed at birth. A slightly hyperechogenic cyst with no increase in size at repeated prenatal scans, was observed in cases 4 and 5; a CC and a cystic lesion at the confluence of the hepatic ducts (without obstruction) were diagnosed postnatally, respectively.


CONCLUSIONS
The ultrasound scan pattern and size allow to make a prenatal differential diagnosis of BCM. Anechoic, small cyst in the hepatic hilum is highly suspicious for BA. Large, echoic or enlarging cyst is strongly suggestive of "obstructed" CC. Echoic, small and stable cyst is more suggestive of "unobstructed" CC.
Casaccia
G
G
Neonatal Surgery Unit, Department of Medical and Surgical Neonatology, Bambino Gesù Children's Hospital, and the ECO B.I. Fetal Diagnosis Center, Rome, Italy.
Bilancioni
E
E
Nahom
A
A
Trucchi
A
A
Aite
L
L
Marcellini
M
M
Bagolan
P
P
D001652:Bile Ducts / Q000002:abnormalities* / Q000601:surgery; D001656:Biliary Atresia / Q000000981:diagnostic imaging; D015529:Choledochal Cyst / Q000000981:diagnostic imaging; D003560:Cysts / Q000000981:diagnostic imaging* / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging*; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000196:embryology; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods; D011247:Pregnancy; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal