Complex Liver Cyst
A complex liver cyst is a fluid-filled area in the liver that shows additional features on imaging, such as internal septations, thickened walls, debris, or enhancement. Unlike simple liver cysts, which are usually benign and require no treatment, complex cysts may need further evaluation to determine their cause. They can be related to infection, bleeding, inflammation, or, less commonly, tumors.
What is it?
A complex liver cyst is a liver cyst that shows features beyond a simple, thin-walled fluid sac. Imaging may reveal internal walls (septations), thick or irregular borders, calcifications, internal debris, or contrast enhancement. These features may indicate prior bleeding into the cyst, infection, inflammation, or—in some cases—a cystic tumor such as a biliary cystadenoma or cystadenocarcinoma.
Radiologists use CT, MRI, and ultrasound to identify these features and assess how concerning they may be. The appearance helps determine whether a cyst likely represents a benign process or if further evaluation, follow-up imaging, or intervention is needed.
Important to Know
Most complex liver cysts are benign, but certain patterns can suggest infection or rare cystic tumors that may require treatment. Symptoms may develop if a cyst becomes large, infected, or bleeds. MRI is often the preferred test for further evaluation because it provides detailed information about the cyst’s internal structure.
Red flag symptoms include fever, worsening abdominal pain, jaundice, or signs of infection, which may require urgent medical attention. Treatment varies from simple monitoring to drainage or surgical removal depending on the underlying cause and imaging features. Regular follow-up imaging may be recommended to monitor any changes.