Pancreatic cysts are often found by chance on a scan done for another reason. Most are harmless and never cause problems. Some types carry a small risk of turning into cancer over time, so they are followed with planned scans. Surgery is advised only when specific worrying features appear.

What are they?

A pancreatic cyst is a fluid-filled sac in or on the pancreas. They are increasingly found because CT and MRI scans are used more often, and they become more common with age. Most people with a cyst have no symptoms from it. The important questions are what type of cyst it is and whether it has any features that need action.

Main types

• Pseudocyst: a collection of fluid after an attack of pancreatitis. It is not a true cyst and is not linked to cancer
• Serous cystadenoma: a benign cyst that very rarely becomes cancerous. It usually needs no treatment unless it causes symptoms
• IPMN (intraductal papillary mucinous neoplasm): a mucus-producing growth arising from the pancreatic ducts. 'Branch-duct' IPMN, the commonest kind, carries a low risk. IPMN involving the main pancreatic duct carries a higher risk and is more often treated with surgery
• Mucinous cystic neoplasm: occurs almost only in women, usually in the body or tail of the pancreas, and is often removed
• Less common types, such as solid pseudopapillary neoplasm and cystic neuroendocrine tumour, which are usually considered for surgery

How the type is worked out

• MRI with MRCP is the preferred test: it shows the cyst, its connection to the pancreatic ducts, and any solid parts, without radiation
• Endoscopic ultrasound (EUS) gives close-up images and can sample fluid from the cyst or tissue from a solid area when the type or risk is uncertain
• Blood tests may include the tumour marker CA 19-9 and blood sugar. CA 19-9 alone cannot diagnose or exclude cancer and is interpreted alongside the scans

Surveillance

Many cysts, especially small branch-duct IPMNs without worrying features, are followed with scans, mostly MRI and sometimes EUS. The interval is set for each person, based on the type and size of the cyst and how it changes. Typically the first check is within 6 to 12 months (sometimes later for very small cysts), and intervals lengthen if it stays stable.

Surveillance only makes sense if surgery would be an option should worrying features appear. For people who are older or have serious health problems, the team may recommend less frequent checks or stopping them. Some guidelines also allow relaxing surveillance after several years of stability. Many IPMNs are followed for as long as you remain fit for surgery, so please do not stop follow-up on your own. Any change to the plan is a shared decision with your specialist.

Features that prompt referral for surgery

If any of these develop, your team will arrange further tests and discuss referral to a specialist pancreatic surgical team:

• Jaundice (yellow eyes or skin) caused by the cyst
• A solid area or nodule inside the cyst that takes up contrast on scans
• Widening of the main pancreatic duct
• Abnormal cells found on sampling
• Rapid growth of the cyst, or a large cyst
• A rising CA 19-9, new diabetes, or pancreatitis caused by the cyst

Pancreatic surgery is a major operation, so the decision balances the risk of the cyst against the risk of the operation.

What you can do

• Keep your scan appointments; regular follow-up allows any change to be found early, when it can be treated
• Stop smoking, which is a risk factor for pancreatic cancer
• Keep a healthy weight, and avoid alcohol completely
• Report new symptoms rather than waiting for the next scan

Common questions

This leaflet is general information and does not replace advice from your own doctor. Version 1.0, October 2026. Next review October 2028.