What is Pancreatic Cysts?

A pancreatic cyst is a fluid filled sac that develops in the pancreas. Often, pancreatic cysts cause no symptoms and are discovered incidentally during an ultrasound, CT or MRI scan performed for other reasons.

Finding a pancreatic cyst does not mean that you have pancreatic cancer. Many pancreatic cysts are entirely benign or have a low risk of becoming cancerous.

However, some pancreatic cysts can develop precancerous changes over time.

Therefore, the important questions are what type of pancreatic cyst you have, whether it has any high-risk features, and whether it needs monitoring or treatment.

What Are Pancreatic Cysts?

The pancreas is a flat and broad organ located behind the stomach. It extends from the upper middle portion of the abdomen to the left side of the abdomen. The pancreas helps the body to digest food by producing digestive enzymes and hormones, including insulin that regulates blood sugar. Pancreatic cysts are fluid-filled sacs that develop within the tissue of the pancreas. It can involve the pancreatic duct. Cyst may vary in size, shape, appearance.

Some cysts develop because of inflammation, while others are related to mutations in pancreatic cells.

If a pancreatic cyst is found, further assessment is recommended to determine the type of cyst and whether it requires monitoring or treatment. At Nobel Gastroenterology Centre, Singapore, our specialists can assess the characteristics of the cyst to understand whether it requires monitoring or treatment.

Are Pancreatic Cysts Cancerous?

Most pancreatic cysts are not cancerous at presentation, but many have the potential to turn into one. This is unique when compared to other cysts like liver cysts which are generally benign.

The risk depends on the type of pancreatic cyst. Some cysts, e.g.intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN), can develop precancerous changes and progress to cancer.

Other lesions, such as serous cystic neoplasms, are considered to be benign (non-cancerous). Serous cystic neoplasms can grow slowly in size over many years, leading to symptoms that eventually require removal, although this occurs infrequently.

Gastroenterologists assess the cyst for high-risk features, such as an increase in the size, changes in cyst appearance, presence of nodules or solid components within the cyst, or dilatation of the pancreatic duct. Abnormal cancer markers like the Ca19-9 or CEA, development of new onset diabetes mellitus, or an unexplained deterioration of diabetes control are worrisome features. Symptoms of abdominal pain and inflammation of the pancreas (pancreatitis) if attributable to the pancreatic cyst, suggest that treatment is required.

Having a pancreatic cyst does not mean that you have cancer. The appropriate step depends on the type of cyst.

What Causes Pancreatic Cysts?

The cause depends on the type of pancreatic cyst.

• Most pancreatic cysts develop without a clear cause. Others may be associated with pancreatitis: Inflammation of the pancreas leading to the development of pancreatic pseudocysts. This is often due to gallstones. In Singapore, less commonly, high triglyceride levels and heavy alcohol consumption may cause pancreatitis.
• Abdominal trauma: Blunt or penetrating injury to the abdomen (e.g. traffic or industrial accident) can damage the pancreas and result in a pseudocyst.
• Mutations in the pancreatic cells or ducts: pancreatic cystic lesions develop because of changes in the cells lining the pancreatic ducts and pancreatic tissue.
• Inherited conditions: Rarely genetic conditions can increase the likelihood of developing pancreatic cysts and tumors.

In many people, the exact reason a pancreatic cyst has developed is not apparent.

What Are the Symptoms of Pancreatic Cysts?

Many pancreatic cysts do not cause symptoms and are found incidentally during imaging of the liver, kidneys, lungs and heart.

When symptoms occur, they may include:

• Upper abdominal pain - typically after meals
• Pain that radiates to the back
• Nausea or vomiting
• Bloating and fullness after a small meal
• Unexplained weight loss
• New onset diabetes mellitus
• Worsening of sugar control in a previously stable diabetic patient
• Diarrhoea with oily stools
• Jaundice, if the cyst affects the bile duct.

These symptoms can also occur with other digestive conditions, so further assessment is needed to determine the cause.

What Are the Different Types of Pancreatic Cysts?

The type of cyst is important because different pancreatic cysts carry different risks.

• Intraductal Papillary Mucinous Neoplasm (IPMN): An IPMN develops within the pancreatic duct and produces a thick fluid with mucous (mucin). Some IPMNs remain stable for many years, while others have a higher risk of developing precancerous or cancerous changes.
• Mucinous Cystic Neoplasm (MCN): A mucinous cystic neoplasm usually develops in the body or tail of the pancreas and is more common in women. It has the potential to become cancerous, so further assessment or surgery may sometimes be recommended.
• Serous Cystadenoma: A serous cystadenoma is usually benign. Small cysts with typical features may be monitored if they are not causing symptoms.
• Pancreatic Pseudocyst: A pancreatic pseudocyst develops following pancreatitis. Unlike other pancreatic cysts, it is caused by inflammation and contains pancreatic digestive enzymes. It is not a tumour and has no risk of cancer.
• Solid Pseudopapillary Neoplasm: This is a rare pancreatic tumour containing both solid and cystic areas. It is more commonly seen in younger women and usually requires specialist assessment.

How Are Pancreatic Cysts Diagnosed?

Pancreatic cysts are often discovered during a scan, such as a CT scan or ultrasound scan of the abdomen.

If a pancreatic cyst is found, a gastroenterologist will review your symptoms, medical history, and scan to understand the size, location and appearance of the cyst, and whether further assessment is needed.

Evaluating the pancreatic cyst involves an MRI scan and the endoscopic ultrasound (EUS) procedure. Both tests are complementary and provide detailed information on the characteristics of the cyst. If the cyst is large, fluid from the cyst may be aspirated for biochemical analysis.

At Nobel Gastroenterology Centre, our gastroenterologist, Dr Eric Wee specializes in pancreatic conditions and performs the endoscopic ultrasound with fine needle aspiration (FNA) procedure. In most countries, only a limited number of gastroenterologists are accredited to perform the EUS procedure. Hence gastroenterologists and surgeons will refer their patients to specialists who are trained to evaluate the pancreas, if an endoscopic ultrasound is required.

Cancer markers like the Ca19-9 may be tested as well. Based on the findings and features identified, the type of cyst and risk of cancer can be determined.

How Are Pancreatic Cysts Treated?

Treatment depends on the type of cyst, symptoms, imaging findings, and estimated risk of cancer.

There are three broad approaches.

1. Monitoring and Surveillance

Most pancreatic cysts do not require immediate treatment. Instead, doctors monitor the cyst with periodic scans to determine whether it changes in size or develops worrisome features.

Both the MRI and endoscopic ultrasound (EUS) are used for surveillance, often in tandem. In individuals with a high risk of pancreatic cancer, surveillance alternates between the MRI scan and EUS. The frequency of follow-up depends on factors such as cyst size and imaging characteristics.

2. Drainage

Symptomatic pseudocysts may require drainage. This is performed under endoscopic ultrasound guidance. Not all pancreatic cysts can be drained. Only pseudocysts that are large and symptomatic require drainage. Cystic tumors (IPMN, MCN, serous cysts) should never be drained; they should be surgically removed if needed.

3. Surgery

Surgery is considered when a pancreatic cyst:

• Has features indicative of cancer or high-grade precancerous changes
• Is confirmed to be a mucinous cyst
• Causes symptoms or complications
• Changes in a concerning way during surveillance (e.g. dilatation of the pancreatic duct, development of a nodule within the cyst, rapid increase in size, etc.)

The type of surgery depends on the location of the cyst within the pancreas. Possible procedures may include removal of the head of the pancreas (Whipple surgery) or the tail end of the pancreas (distal pancreatectomy).

Are There Medications for Pancreatic Cysts?

Unfortunately, medicines are ineffective in treating pancreatic cysts. They cannot make a cyst shrink or disappear.

Medication may be given to treat cyst-related complications. For example, an individual with pancreatitis may require treatment for pain and nausea. Pancreatic enzymes may be needed if digestion is a problem.

When Should You See a Doctor?

Many pancreatic cysts do not cause symptoms and are found during scans for other reasons. If a pancreatic cyst has been identified, it is important to follow your doctor's advice on whether further assessment or monitoring is needed.

See a doctor if you experience:

• Persistent or recurring upper abdominal pain
• Pain that spreads to the back
• Unexplained weight loss
• Ongoing nausea or vomiting
• Feeling full quickly when eating
• Yellowing of the skin or whites of the eyes
• New or worsening digestive symptoms

At Nobel Gastroenterology Centre, Dr Eric Wee, Senior Consultant Gastroenterologist, assesses pancreatic and digestive conditions and offers advanced endoscopic procedures, including the endoscopic ultrasound (EUS).