Benign, congenital or developmental, fluid-filled space with wall derived from biliary endothelium

Anechoic lesion with posterior acoustic enhancement, well-defined back wall, and no internal vascularity

May be unilocular or multilocular with barely perceptible septations

Ultrasound

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  Often demonstrates septations to better advantage than CT or MR

Current theory

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  True hepatic cysts arise from hamartomatous tissue

When > 10 in number, consider fibropolycystic diseases

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  Autosomal dominant polycystic liver disease

  
  
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  Autosomal dominant polycystic kidney disease

  
  
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  Biliary hamartomas

Biliary cystadenoma/cystadenocarcinoma

Cystic metastases

Pyogenic abscess

Echinococcal/hydatid cyst

Biloma

Lined by single layer of cuboidal bile duct epithelium

Surrounding thin rim of fibrous stroma

Examine with color or power Doppler to exclude pseudoaneurysm, which can have similar appearance on grayscale imaging

High-frequency linear transducers with coded harmonic imaging setting can help to demonstrate cystic nature of anterior hepatic cysts