Choledochus-Zyste

School ager
with abdominal pain after trauma. Axial CT with contrast of the abdomen (upper left) shows a large round low density structure inferior to the liver and separate from the gall bladder. Transverse and sagittal US of the liver show the round structure to be cystic and in communication with a dilated biliary tree. Delayed image (lower left) from a hepatobiliary scintigraphy exam shows concentration of radiotracer into the round structure which is slowly excreted into the bowel. AP image of an intraoperative cholangiogram (lower right) shows dilation of the intrahepatic and extrahepatic biliary tree with free flow of contrast into the bowel.The diagnosis was choledochal cyst causing biliary obstruction.
pediatricimaging.org • CC-by-nc-sa 4.0
Is that you,
choledochal cyst?. Cystic structure with lobulated margins next to the common bile duct, which shows normal calibre.
www.eurorad.org • CC by-nc-sa-4.0
Is that you,
choledochal cyst?. T2 weighted axial (A) and coronal images (B). Note the communication between the cystic formation and the common bile duct (arrow).
www.eurorad.org • CC by-nc-sa-4.0
Is that you,
choledochal cyst?. T2 weighted axial (A) and coronal images (B). Note the communication between the cystic formation and the common bile duct (arrow).
www.eurorad.org • CC by-nc-sa-4.0
Unjaundiced
preschooler with vomiting and abdominal pain. Axial (above left) and coronal (above right) CT without contrast of the abdomen show a large cystic lesion between the right kidney and pancreas with extensive surrounding inflammation. The gall bladder was normal. AP image from intraoperative cholangiogram (below) shows the lesion represents diffuse dilation of the common bile duct with free passage of contrast into the small bowel. The diagnosis was choledochal cyst Type I.
pediatricimaging.org • CC-by-nc-sa 4.0
5 types of
Choledochal cysts. Type I: dilatation of extrahepatic biliary duct; Type II: Cyst from common bile duct (CBD); Type III: choledochocele or dilatation of distal part of CBD, type IV: dilatation of both extrahepatic and intrahepatic duct; Type V: Caroli disease, Dilatation of intrahepatic duct only. CHD: common hepatic duct, LHD: left hepatic duct and RHD: right hepatic duct.
Wikipedia • CC-BY-SA-3.0
Medullary
sponge kidney • Caroli disease with medullary sponge kidney and nephrocalcinosis - Ganzer Fall bei Radiopaedia
Desai P, Caroli disease with medullary sponge kidney and nephrocalcinosis. Case study, Radiopaedia.org (Accessed on 06 Jan 2023) https://doi.org/10.53347/rID-10805 • CC by-nc-sa 3.0 (modified)
Intraductal
papillary mucinous neoplasm • Choledochal cyst - type I - Ganzer Fall bei Radiopaedia
Salam H, Choledochal cyst - type I. Case study, Radiopaedia.org (Accessed on 25 Jan 2023) https://doi.org/10.53347/rID-8105 • CC by-nc-sa 3.0 (modified)
Newborn with
a cystic right upper quadrant mass on prenatal US. Transverse (above left) and sagittal (below left) US of the liver shows an oval shaped cystic mass in the porta hepatis that is separate from the normal gallbladder. Anterior image of a HIDA scan obtained 40 minutes after radiotracer injection (above right) shows radiotracer localization in the liver, in a large oval mass medial to the liver, in the gallbladder which overlies the inferior and lateral border of the liver, and in the bowel. AP image from an intraoperative cholangiogram (below right) shows contrast being injected into the gallbladder which is flowing down the cystic duct and then filling an oval mass superior to the gallbladder. The contrast filled mass contains an air bubble and is partially obscured by a surgical retractor overlying it.The diagnosis was choledochal cyst.
pediatricimaging.org • CC-by-nc-sa 4.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Choledochal cysts represent congenital cystic dilatations of the biliary tree. Diagnosis relies on the exclusion of other conditions (e.g. tumor, gallstone, inflammation) as a cause of biliary duct dilatation.

Epidemiology

Choledochal cysts are rare, with an incidence of 1:100,000-150,000. Although they may be discovered at any age, 60% are diagnosed before the age of 10 years . There is a strong female predilection with M:F ratio of 1:4. There is a greater prevalence in East Asia.

Clinical presentation

Classical presentation includes the triad of :

This triad is however only present in ~40% (range 19-60%) of cases, with palpable mass being the least common manifestation.

Pathology

Their etiology is uncertain, but a close association with the anomalous formation of the pancreaticobiliary ductal junction is reported in some subtypes . Due to this anomaly, there is a large common channel draining pancreatic and bile duct. Thus the pancreatic juices cause cholangitis and bile duct wall destruction, which together with distal stenosis due to scarring result in the formation of a choledochal cyst.

Associations

A number of associations are recognized, including :

Classification

Commonly accepted classification currently is one devised by Todani et al. There are five main types, with several subtypes some of which can be pathologically unrelated:

  • type I: most common, accounting for 80-90%  (this type can present in utero)
    • Ia: dilatation of extrahepatic bile duct (entire)
    • Ib: dilatation of extrahepatic bile duct (focal segment)
    • Ic: dilatation of the common bile duct portion of extrahepatic bile duct
  • type II: true diverticulum from extrahepatic bile duct
  • type III: dilatation of extrahepatic bile duct within the duodenal wall (choledochocoele)
  • type IV: next most common
    • IVa: cysts involving both intra and extrahepatic ducts
    • IVb: multiple dilatations/cysts of extrahepatic ducts only
  • type V: multiple dilatations/cysts of intrahepatic ducts only (Caroli disease)

The Todani classification scheme has been called into question in surgical literature, with claims that it may unfairly link multiple distinct processes into a spuriously coherent grading scheme .

The Komi classification classifies choledochal cyst into 3 types based on the anomalous union of the pancreatic-bile duct (AUPBD) .

Radiographic features

Imaging of the biliary tree can be achieved with ultrasound, CT, direct contrast studies (ERCP, PTC) or MRI.

Ultrasound

The key to the diagnosis is a dilated cystic lesion which communicates with the bile duct and is separate from the gallbladder. A careful search for other causes needs to also be undertaken (see differential below), remaining cognizant that both stone formation and malignancy are associated with choledochal cysts.

CT / MRI

Findings are similar to ultrasound, with a greater ability to demonstrate intrahepatic disease and complications.

Treatment and prognosis

Patients with type I, II, or IV cysts usually undergo surgical resection of the cyst due to the risk of malignancy. A number of possible approaches exist, depending on cyst location and other factors. Typically a Roux-en-Y hepaticojejunostomy is performed .

Complications

The two most frequent complications of choledochal cysts are stone formation and malignancy. Complications include:

  • stone formation: most common
  • malignancy
  • the cyst may rupture leading to bile peritonitis
    • most frequently seen in neonates
  • pancreatitis

Differential diagnosis

General imaging differential considerations include:

See also

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Choledochuszyste:
Normvarianten
des Gallenwegssystems
jmedicalcasereports.biomedcentral.com • CC-by-4.0
Duodenaldivertikel
 
Wikipedia • CC BY-SA 4.0
zystische
Pankreasläsionen
insightsimaging.springeropen.com • CC-by-4.0