Liver cyst

3 things to know first

1. Simple liver cysts are usually benign. They are one of the most common liver findings on imaging.
2. They often cause no symptoms. Most people never know they have a liver cyst unless it is seen on a scan.
3. Size and features guide follow-up. Large cysts or cysts with internal structures may need closer attention.

What it is

A liver cyst is a fluid-filled sac in the liver. Simple liver cysts have thin walls and contain clear fluid. They are different from cysts related to polycystic liver disease, which are numerous and may run in families.

The liver has many important jobs, including processing nutrients and filtering blood. A simple cyst does not usually affect these functions.

Why it appears on your report

Liver cysts are frequently found incidentally on ultrasound, CT, or MRI performed for other reasons. The radiologist describes the cyst's size, location, and whether it has any internal features. A simple cyst is usually reported as a benign finding.

How serious is it

Most liver cysts are not serious:

• Simple cysts (thin wall, clear fluid, no internal structures) are almost always benign and usually need no treatment.
• Large cysts may cause a sense of fullness, discomfort, or pain in the upper right abdomen.
• Cysts with internal walls, solid parts, or irregular features are less common and may need further evaluation to rule out infection or other conditions.

Your doctor will consider the cyst's appearance and whether you have symptoms.

When to seek care urgently

Simple liver cysts rarely cause emergencies. Seek urgent care if you have:

• Severe or sudden pain in the upper right abdomen
• Fever with abdominal pain
• Jaundice (yellowing of the skin or eyes)
• Persistent vomiting

These may indicate a cyst infection, bleeding, rupture, or another liver problem.

What usually happens next

1. Confirm it is simple. The radiologist's description is usually sufficient. If the cyst has unusual features, a contrast-enhanced scan or MRI may be suggested.
2. Check liver function if needed. Blood tests are sometimes done, especially if the cyst is large or there are many cysts.
3. Decide on follow-up. Simple cysts usually need no follow-up. Cysts with complex features may be monitored with imaging.
4. Treat symptoms if present. Large or symptomatic cysts can sometimes be drained or treated surgically if they significantly affect quality of life.

A simple analogy

Imagine the liver as a loaf of bread. A simple liver cyst is like a small bubble of water inside the loaf. It does not change the taste or function of the bread; it is just a pocket of fluid sitting inside.

Further reading

• NHS — Liver disease
• Mayo Clinic — Polycystic liver disease