Choledochal
Cyst
Epidemiology and Etiology:
- Congenital
- Presenting in
children < 10y usually
- F:M = 3-4:1
- Asians > others
- Anomalous pancreaticobiliary
junction between the CBD and duct of Wirsung (most)
- Secondary to extrahepatic
biliary tree surgery (minority)
Common sites:
Gross features:
- varying gross
appearances
- segmental dilation
- cylindrical
dilation
- diverticuli
- choledochocele
(cystic lesion protruding into the duodenal lumen)
- up to 2L capacity
- coarsely granular
surface
- adhesions to
adjacent structures (adults > children)
- predispose to stone
formation, stenosis, and stricture
- type 1 (85-90%):
- fusiform or
saccular dilation of CBD
- complete obstruction
of distal CBD (in infants, but not usually in adults)
- distal narrowing is
common
- type 2:
- type 3:
- dilation of the
teriminal end of the CBD within the duodenal wall
- type 4:
- multiple
dilatations of CBD with intrahepatic and / or extrahepatic duct
involvement
- type 5:
- single or multiple
- confined to
intrahepatic ducts
Histologic features:
- fibrotic wall with
varying amounts of smooth muscle
- intact or denuded columnar
epithelial lining
Immunophenotype:
Marker:
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Sensitivity:
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Specificity:
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Molecular features:
Other features:
- Clinical features:
- In adults, significant
increased risk of bile duct carcinoma (up to 15%)
- Adenocarcinomas (most)
- Squamous cell
carcinoma
- Anaplastic carcinomas
- Other complications:
- Cholangitis
- Pancreatitis
- Liver abscess
- Cirrhosis
- Type 5 cysts may be
associated with hepatic fibrosis (Caroli’s disease)
References:
- Robbins &
Cotran Pathologic Basis of Disease (2005)