Clinical Presentation

A 45-year-old woman presents with right upper quadrant pain without fever or leukocytosis.

Contrast-enhanced computed tomography (CT) shows a well-circumscribed, multiloculated cystic lesion (arrow) in the right lobe of the liver. No enhancing nodular components are visible. Scattered, smaller low-density foci are seen in the liver, most likely cysts.

Differential Diagnosis

• Biliary cystadenoma: This is the strongest contender as the diagnosis for a multiloculated, smoothly marginated cystic lesion in the liver without clinical signs of infection.

• Hepatic cyst: This can have a similar appearance in a minority of cases. This patient has other low-density lesions suspicious for simple cysts.

• Echinococcal cyst: This often results from infection by Echinococcus granulosus or Echinococcus multilocularis