Choledochal cysts are an uncommon abnormality defined as abnormal cystic dilation of intrahepatic,
extrahepatic bile duct,
or both [1].
This pathology occurs more frequently in childhood,
however it can occur in adults.
Choledochal cysts occur in about one in 100,000–150,000 births in Western countries.
The incidence is much higher in Asian countries,
approximately 1/1000,
with a greater predilection for women [2].
Multiple theories have been proposed to explain the physiopathogenesis,
however until now no single pathological mechanism has been found to explain them.
Anomalous pancreaticobiliary junction seems to have a predominant role.
Pancreatic and common bile duct are joined before the ampulla of Vater,
forming a single long duct in which pancreatic and biliary secretions are mixed,
leading to a chronic inflammatory process,
deteriorating bile duct wall,
causing dilation [3].
Choledochal cysts have a strong association with bile duct cancer,
especially with cholangiocarcinoma,
occurring in 10 to 30% of patients with this pathology.
This can develop from the cyst wall or from remaining undilated tissue.
Risk depends on type of cyst and age,
being in people over 50 years between 40 to 50% [4].
Clinically choledocal cysts present in childhood with jaundice,
pain and abdominal mass in 85% cases.
In adult life this triad is infrequent and the symptoms are more insidious,
with symptoms related to pancreatitis or cholangitis.
Laboratory tests are not specific,
among the most frequent alterations are hyperamylasemia and bilirubin elevation [4].
Imaging studies play an important role in diagnosis,
the most commonly used are ultrasound,
computed tomography and magnetic resonance cholangiopancreatography. Of the invasive methods available,
the most commonly used is endoscopic retrograde cholangiopancreatography (ERCP) [5].
It is known that choledochal cysts are benign.
However,
the cyst should be removed due to the high risk of developing neoplasia,
especially cholangiocarcinoma,
and other pathologies such as choledocholithiasis,
cholangitis and pancreatitis.
Surgical procedure of choice is excision of the cyst and hepaticojejunostomy with Roux-en-Y anastomosis.
Early management is associated with a low incidence of complications.
After surgery,
strict follow-up must be carried out,
which includes laboratory and imaging studies to control the anastomosis and the evaluation of the remaining tissue due to risk of cancer [5-6].