Liver cysts are sacs filled with air, water or semi-solid material, according to the Section of Gastrointestinal Surgery at the University of California, San Francisco. A cyst rarely impairs the functions of the liver, but there might be a need to surgically remove it if it gets large and painful.
Most liver cysts grow slowly, and the cause for the development of liver cysts is unknown, states the American Liver Foundation. The cysts can be present at birth, or they may develop over time. Patients with large liver cysts may experience bloating and pain in the upper part of the abdomen. Liver cysts may be diagnosed using an ultrasound or an abdominal CT scan.