Diagnostic Ultrasound - Abdomen and Pelvis

Peribiliary Cyst
TERMINOLOGY
Synonyms
• Retention cyst of peribiliary gland
Definitions
• Cystic dilation of obstructed periductal glands of bile ducts
IMAGING
General Features
• Best diagnostic clue
○ Well-defined cystic lesions of round/oval/tubular shape
along portal triads
• Location
○ Along portal tracts in hepatic hilum
○ Adjacent to large intra- and extrahepatic ducts
○ Occasionally seen in peripheral liver
• Size
○ Variable, 2 mm to 2 cm
• Morphology
○ Usually multiple rounded cysts along portal triads
Ultrasonographic Findings
• Cluster of multiple small anechoic structures along portal
triads most commonly at hepatic hilum
CT Findings
• Well-defined, water attenuation, round/oval/tubular
structures
• Smooth, thin walls; no internal structures
• No enhancement on CECT
• Different configurations
○ Separate discrete cysts coursing along hilar/proximal
intrahepatic portal vein
○ Linear cluster of cysts with "string of beads" appearance,
mimicking sclerosing cholangitis
○ Confluent tubular cysts resembling dilated bile ducts
MR Findings
• T1WI: Iso- or hypointense compared to liver parenchyma
• T2WI: Markedly hyperintense due to fluid content
• T1WI C+: No enhancement
• Delayed phase:No contrast media filling cysts in
hepatobiliary phase of MR using hepatocyte-specific
contrast agent
○ Due to lack of communication with biliary system
Radiographic Findings
• Cholangiography:Nonopacification of cysts due to lack of
communication with biliary system
DIFFERENTIAL DIAGNOSIS
Biliary Ductal Dilatation
• Dilated bile ducts along portal triads typically caused by
downstream obstructive process
• Tubular in configuration
Caroli Disease
• Congenital, multifocal, segmental, saccular dilatation of
intrahepatic bile ducts
• "Central dot" sign on CECT: Enhancement of portal radicles
within cysts
• May coexist with peribiliary cysts
Periportal Edema/Inflammation
• CT: Circumferential zones of decreased attenuation around
portal vein branches
• US: Echogenic appearance of portal triads; not typically
confused with peribiliary cysts on US
• Seen in various conditions, including hypervolemia, cardiac
congestion, hepatitis, etc.
PATHOLOGY
General Features
• Etiology
○ Disturbed portal venous flow, periductal fibrosis and
inflammation →obliteration of neck of peribiliary glands
→formation of retention cyst
○ Gene expression of autosomal dominant polycystic
kidney disease (ADPKD) in peribiliary glands
○ Infrequent complications of liver transplantation
• Associated abnormalities
○ Chronic hepatitis, cirrhosis, portal hypertension, portal
vein thrombosis
○ AD polycystic disease
○ Caroli disease
Gross Pathologic & Surgical Features
• Predominantly serous, rarely mucinous cysts
Microscopic Features
• Single layer of epithelial lining with thin fibrous tissue layer
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Generally asymptomatic from cysts
○ Obstructive jaundice may occur
– Associated with end-stage liver cirrhosis
○ Symptoms related to underlying liver disease
Demographics
• Epidemiology
○ On pathology:20% of normal population and 50% of
patients with cirrhosis
○ On CT:3% of normal population, 95% of patients with
cirrhosis, and 20% of patients with AD polycystic disease
Natural History & Prognosis
• May increase in size and number of cysts in time with
progression of cirrhosis
SELECTED REFERENCES
1. Kai K et al: An autopsy case of obstructive jaundice due to hepatic multiple
peribiliary cysts accompanying hepatolithiasis. Hepatol Res. 38(2):211-6,
2008
2. Terayama N et al: Terada T, Nakanuma Y, Shinozaki K, et al. Peribiliary cysts in
liver cirrhosis: US, CT, and MR findings. 19(3):419-23, 1995
3. Baron RL et al: liver disease: imaging-pathologic correlation. AJR Am J
Roentgenol. 1994 Mar;162(3):631-6. 162(3):631-6, 1994
4. Itai Y et al: Hepatic peribiliary cysts: multiple tiny cysts within the larger portal
tract, hepatic hilum, or both. Radiology. 191(1):107-10, 1994
Diagnoses: Liver
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