Also known as a hepatic cyst, a simple liver cyst is a thin-walled sac filled with air, fluid, or semi-solid material found on the liver; they typically produce no signs or symptoms. Simple liver cysts are normally benign and rarely impair the liver’s ability to function. Patients typically present with a single liver cyst, although multiple cysts are sometimes found.
A relatively common condition, simple liver cysts are most often benign and pose no problems or health risks. They are usually detected by chance during other causes of testing, usually through abdominal ultrasound or computerized tomography (CT) scans.
The exact cause of simple liver cysts is unknown. Liver cysts can be present at birth or can develop over time; if congenital, they usually grow slowly and are often not detected until adulthood.
In rare cases, liver cysts may indicate a serious, underlying condition such as polycystic liver disease (an inherited serious disorder associated with multiple cysts of varying size), echinococcosis (a parasitic infection), or liver cancer.
Most liver cysts do not cause any symptoms. However, if a cyst becomes large, it can cause bloating and pain in the upper right part of the abdomen. Occasionally, a cyst may become large enough to feel through the abdomen. A very large cyst may impact other organs; it may cause symptoms that include nausea, vomiting, poor appetite, and a yellowing of the skin and eyes (jaundice).
Because most liver cysts do not cause symptoms, they are usually detected due to unrelated ultrasound or computerized tomography (CT) scans. It is not uncommon to find one or several small cysts on the liver when a patient has an ultrasound or CT scan of the abdomen for a different reason. US and CT scans are the best imaging tools to show liver cysts which contain liquid and/or solid areas. A biopsy may be recommended to help determine the nature of the cyst.
A blood test will rule out a parasite as the cause of the liver cyst.
Generally, only patients with symptoms require treatment which consists of surgically removing a substantial portion of the cyst wall. Removing only the fluid from the cyst is not an effective treatment because the cyst may fill up again, sometimes quickly. The surgical procedure is performed laparoscopically, requiring only a few small incisions and a fast recovery time. There is little chance of cyst recurrence if part of the cyst wall is removed during surgery.
If a parasite is found as the cyst cause, antibiotics are the common course of treatment.