Liver Cyst

What is a liver cyst?

Liver cysts are non-cancerous, fluid-filled sacs that occur in the liver. Although liver cysts rarely affect liver function, some can grow big enough to lead to complications. Liver cysts can exist as a single cyst (a simple liver cyst) or multiple cysts, especially in a condition known as polycystic liver disease (PLD). 

What causes liver cysts?

Liver cysts are congenital, which means they have existed since birth. Even though some people are born with liver cysts, they can go undetected until symptoms present themselves later in life. However, liver cysts can also occur because of bile duct malformation or even degenerative changes in the liver due to ageing or trauma.

Additionally, studies have also suggested that some liver cysts are formed due to a parasite known as echinococcus. This parasite is often found near cattle and sheep habitats, so a person can get infected by consuming contaminated food or water.

On the other hand, a person with a family history of PLD is more likely to develop PLD, too. 

What are the symptoms of liver cysts?

Generally, individuals with liver cysts do not experience any symptoms. However, if they do, they may present in the following ways: 

• Acute stomach pain: some individuals with liver cysts may experience pain or discomfort in the upper right abdomen.
• Bloated or distended stomach: large cysts can cause a sensation of fullness or bloating in the abdomen.
• Nausea and vomiting: in some individuals, liver cysts may lead to nausea and vomiting.
• Jaundice: if a cyst obstructs the bile ducts, it can result in jaundice, characterised by yellowing skin and eyes.
• Heartburn: if a liver cyst is large enough, it may push up against the stomach, causing stomach acid reflux back up into the oesophagus, causing heartburn.
• Loss of appetite: individuals may experience a loss of appetite or a feeling of fullness after eating a small amount of food.
• Shortness of breath: very large cysts can compress nearby organs or push upwards to the diaphragm, affecting the expansion of the lungs and making breathing difficult.

What is the difference between liver cysts and benign liver tumours?

Both liver cysts and benign liver tumours are non-cancerous growths that develop within the liver. However, they are different in many aspects. For one, liver cysts are fluid-filled sacs, whereas benign liver tumours are usually solid masses of cells. 

Both liver cysts and benign liver tumours are generally benign and asymptomatic and only cause symptoms like abdominal discomfort if they grow large enough. Management  is based on several factors, such as:

• Size
• Symptoms that they exhibit
• Potential or risk of complications

Who is at risk of liver cysts in Singapore?

Liver cysts are rare, but some individuals are at an increased risk of developing them. Risk factors for developing liver cysts include:

• Genetics: some individuals may inherit a genetic predisposition to developing liver cysts, while individuals with a family history of liver cysts or PLD may have an increased risk.
• Age: liver cysts are more common in individuals between 40 and 70, with only 10-15% developing symptoms.
• Gender: women are more prone to liver cysts than men. 
• Medical conditions: individuals with conditions such as polycystic kidney disease and biliary disorders may have an increased likelihood of developing liver cysts.

How are liver cysts diagnosed?

Liver cysts are often incidentally detected when a patient undergoes an imaging test, such as an ultrasound, a computed tomography (CT) scan, or magnetic resonance imaging (MRI), for another condition.

If a liver cyst is discovered, you may need to undergo some tests. Some of these tests may include:

• Blood tests: blood tests, including a liver function test, will be conducted to analyse liver health and rule out other liver conditions. A serodiagnosis test will also be performed to identify specific antibodies that may be present in the blood. 
• Imaging: an ultrasound, CT scan or MRI scan may be needed to characterise the cysts and for future surveillance.
• Fluid analysis: a cyst fluid aspiration may be conducted to rule out other liver conditions or confirm its nature.

What are the treatment options for liver cysts in Singapore?

Most simple liver cysts do not require treatment. However, if they proliferate and cause symptoms, your doctor may recommend surgical removal.

Meanwhile, for a cyst that requires intervention or surgery, these are the options:

• Cyst fenestration: large or symptomatic benign cysts can be removed by cyst fenestration, in which the cyst is drained by removing the cyst’s wall.
• Hepatic resection: a hepatic or liver resection involves removing parts of the liver that are affected by cysts. This is recommended if the cyst appears to be cancerous. 
• Liver transplant: if PLD causes loss of healthy liver tissue and liver failure, a liver transplant may be recommended.
• Percutaneous aspiration: large and symptomatic cysts may be drained using a needle inserted through the skin under imaging guidance (ultrasound or CT scan). This procedure, known as percutaneous aspiration, can provide temporary relief. 
• Sclerotherapy: in some cases, after aspiration, a sclerosing agent may be injected into the cyst to prevent it from refilling with fluid.

Frequently asked questions

How serious is a cyst on the liver?

Most cysts are not cancerous and do not require intervention. They also do not cause acute symptoms unless there is rupture or bleeding. A ruptured liver cyst can result in fever, acute abdominal pain, and infection. Antibiotics are the course of treatment for infection due to a ruptured liver cyst.

Can a CT scan tell if a liver cyst is cancerous?

Yes, a CT scan can help differentiate between a benign liver cyst and a cancerous lesion in the liver. While liver cysts typically appear as well-defined, fluid-filled structures with thin walls on a CT scan, cancerous lesions may exhibit different characteristics.

Are liver cysts painful?

Liver cysts may or may not cause pain. Small cysts often do not produce symptoms, while larger cysts can cause discomfort or pain, particularly if they press against other organs or stretch the liver capsule.