The average age of our patients was 5 years,
mostly female (n = 12).
Abdominal pain was the most common clinical sign.
All patients were scanned by ultrasound,
11 cases underwent abdominal CT with contrast agent injection,
while a Magnetic Resonance Cholangiopancreatography (MRCP) was performed in 7 patients.
Ultrasound is the first-line examination with a specificity that varies between 71% and 97% [1].
The choledocal cyst appears as a cystic formation well- defined thin-walled (fig.1,
2,
3) sometimes containing an echogenic material corresponding to the Biliary Sludge (fig.4).
It sits in contact with the portal vein and the gallbladder,
communicating with the bile ducts which can be dilated [1].
Ultrasound also allows the study of the state of the intrahepatic bile ducts and possibly can detect signs suggestive of a complication.
The differential diagnosis arises in the neonatal period with biliary atresia (cystic form),
and in children and the young adult with a dilatation of the bile ducts upstream of a choledocholithiasis or a cystic lesion of the head of the
CT scan allows a good characterization of the cyst which appears as a mass of the hepatic hilum,
in contact with the head of the pancreas,
iso or hypo dense thin walled,
unmodified after the injection of the contrast product.
The CT also allows the study of the distal portion of the common biliary duct,
the head of the pancreas,
the gallbladder,
and finally allows the study of possible complications (fig.
5,6).The CT cholangiography allows visualizing the accumulation of the contrast medium,
excreted in the bile duct,
in the cyst and allows a precise mapping of the biliary tree [2].
Magnetic Resonance Cholangiopancreatography (MRCP),
using heavily T2-weighted sequences (HASTE sequences),
is the best test to diagnose acholedochal cyst (fig.
7,8,9).
It is a recent,
non-invasive technique that allows a better analysis of the biliary and pancreatic ducts and bilio- pancreatic junction,
as it makes it possible to rule out differential diagnoses [3,4].
All these examinations allowed us to objectify a cystic dilatation of the bile duct classified type I according to Todani [5] in 80% of cases,
and a type IVa in 20% of the patients.
Treatment consisted of resection of the cyst with hepato-jejunal anastomosis associated with cholecystectomy with good postoperative outcome.The anathomopathological study of the cysts showed no evidence of malignancy in all children,
an aspect of hepatic cirrhosis was observed in one case.