Pancreatic Cysts

What is a pancreatic cyst?

A pancreatic cyst is a fluid-filled growth on the inside or outside of your pancreas. There are different types, made of slightly different cellular materials. Some types are neoplastic, and others are nonneoplastic. Neoplastic cysts have the potential to become cancerous. Nonneoplastic types don’t.

What does a cyst on the pancreas mean?

Some pancreatic cysts seem to be related to inflammation (pancreatitis), but most occur for unknown reasons. Most pancreatic cysts won’t cause any problems. Rarely, a neoplastic type of cyst can be the start of pancreatic cancer. This is more likely if you have a family history of pancreatic cancer.

Should I be worried about a pancreatic cyst?

If your healthcare provider discovers a pancreatic cyst on your imaging scan, they’ll classify it right away as low, medium or high risk, based on the image and whether you have symptoms. If it’s low risk, there’s likely nothing to worry about. If it’s medium or high risk, they’ll treat it according to their guidelines.

Most pancreatic cysts will simply go under surveillance. Healthcare providers keep an eye on them to see if they change over time. If a cyst changes from low to medium risk, they’ll take a biopsy to learn more about it. If a cyst changes from medium to high risk, they’ll schedule surgery to remove it.

How common are pancreatic cysts?

Studies suggest that approximately 10% of CT scans (computed tomography scans) and MRIs (magnetic resonance imaging) discover pancreatic cysts. They’re usually an accidental finding on imaging tests taken for another reason. Since most pancreatic cysts don’t cause symptoms, we don’t know how many other people might have them without being aware of it.

What percentage of pancreatic cysts are cancerous?

Less than 1% of pancreatic cysts turn into cancer. But up to 30% of pancreatic cysts have the potential to turn into cancer. This is why healthcare providers keep an eye on them. Most precancerous cysts grow and change very slowly, so regular surveillance is likely to spot cancerous changes early in the process.

What are the different types of pancreatic cysts?

Neoplastic (precancerous) cysts are also called pancreatic cystic neoplasms (PCN). They include:

• Intraductal papillary mucinous neoplasms. These are the most common type of neoplastic cysts. They grow on the pancreatic duct. Their fluid is a mixture of pancreatic juices and mucin, which is one of the components in mucus. This mucin may cause the pancreatic duct to swell.
• Mucinous cystic neoplasms. These less-common mucinous neoplasms almost exclusively affect females over the age of 50. They grow on the body of the pancreas.
• Solid pseudopapillary neoplasms. These rare neoplasms have both solid and liquid parts. They tend to affect females, often in their 20s and 30s.
• Cystic pancreatic neuroendocrine tumors. Pancreatic neuroendocrine tumors (also called islet cell tumors) are rare. They’re usually solid tumors, but sometimes they look like cysts.

Nonneoplastic (benign) cysts include:

• Simple cysts (retention cysts). These benign cysts grow within the pancreas, apart from the pancreatic duct. They’re lined with a single layer of epithelial cells. They mostly affect children.
• Serous cystadenomas. These relatively common cysts are benign, but they can cause complications by growing too large and sometimes need surgical removal.
• Mucinous nonneoplastic cysts. These are benign mucin-producing cysts that healthcare providers have to examine to tell apart from the neoplastic types.
• Lymphoepithelial cysts. These rare benign cysts appear mostly in males.

Pancreatic pseudocysts are sometimes mistaken for cysts. A pseudocyst isn’t a growth, however. It’s a pocket of fluid that forms when pancreatic juices leak from your pancreas. Pseudocysts are benign.

What are the symptoms of a pancreatic cyst?

Most pancreatic cysts don’t cause any symptoms. They might cause symptoms if they grow large enough to interfere with your pancreatic duct, biliary tract or gastrointestinal (GI) tract. Possible symptoms include:

• Abdominal pain.
• Back pain.
• Loss of appetite.
• Unexplained weight loss.
• Bloating.
• Indigestion.
• Nausea.
• Jaundice.
• Light-colored, greasy poop (steatorrhea).
• A lump in your abdomen.

What causes pancreatic cysts?

Pancreatic cysts are abnormal growths, which means that a genetic mutation occurred. But researchers don’t know why these occur. They might be partly hereditary and partly triggered by other factors, like inflammation and aging. A small percentage of cysts directly relate to hereditary conditions.

Hereditary syndromes associated with pancreatic cysts include:

• Von Hippel-Lindau disease.
• Polycystic kidney disease.
• Cystic fibrosis.

Risk factors associated with pancreatic cysts include:

• Advancing age. Pancreatic cysts become more common as you get older. They affect an estimated 25% of people in their 70s.
• Pancreatitis. Some types of cysts develop with pancreatitis. Other types can cause pancreatitis.
• Family history. You may be more likely to have pancreatic cysts if you have a family history of pancreatic cancer, or if you have a hereditary syndrome associated with cysts.

What complications can pancreatic cysts cause?

Complications are rare, but may include:

• Pancreatic duct obstruction. Certain mucinous neoplasms can secrete mucin into the pancreatic duct, causing it to swell and eventually clog. This prevents pancreatic enzymes from passing through the duct to your small intestine. The enzymes back up in your pancreas and irritate it, causing pancreatitis. Meanwhile, your digestive system doesn’t get the enzymes it needs.
• Bile duct obstruction. A large cyst that compresses a bile duct can prevent bile from flowing through it (cholestasis). This can cause bile to back up, irritating your bile ducts and the organs connected to them. Bile will also leak into your bloodstream, causing symptoms of illness.
• Gastrointestinal obstruction. A large cyst that compresses your stomach or intestine may cause various gastrointestinal symptoms, such as stomach pain or discomfort, fullness, cramping and loss of appetite. In extreme cases, it may prevent food from passing through your GI tract.
• Pancreatic cancer. A small percentage of cysts can turn into cancer, most commonly adenocarcinoma. Pancreatic cancer has a tendency to spread, so catching it early is key.

How is a pancreatic cyst diagnosed?

Healthcare providers diagnose a pancreatic cyst using:

• Radiology: High-quality imaging, like a CT or MRI scan, can detect pancreatic cysts. Some types of cysts are immediately recognizable in radiology, but others need additional testing to identify the type or to check for cancer cells. In these cases, healthcare providers need to take a sample of the cyst (biopsy).
• Endoscopic ultrasound / Fine needle aspiration (EU-FNA): A procedure called endoscopic ultrasound allows a provider to access a pancreatic cyst through a tiny endoscope, guided by a tiny ultrasound wand. They use a fine needle to take tissue and fluid samples for analysis (fine needle aspiration).
• Fluid analysis: Healthcare providers analyze the content of the cystic fluid in a lab to determine the type. This is also called cytology. They look for things like mucin, which can help identify mucinous neoplasms, and tumor markers like carcinoembryonic antigen (CEA), a blood protein that can help predict cancer.

What is the treatment protocol for pancreatic cysts?

Treatment options include:

• Surveillance.
• Biopsy.
• Removal by surgery.

Most cysts are treated with surveillance. That means you’ll have periodic imaging scans to check on your cysts. You’ll have EU-FNA and fluid analysis to investigate any suspicious changes. If the results raise concern for cancer, your provider might recommend removal, depending on your fitness for surgery.

Do pancreatic cysts go away?

Some types of benign cysts may shrink or even disappear on their own, but neoplastic types don’t. Most continue to grow, although very slowly. Healthcare providers watch them to track their growth. As long as they remain small and don’t grow or change significantly, healthcare providers leave them alone.

How fast do pancreatic cysts grow?

Different types of pancreatic cysts grow at different rates, but overall, they grow slowly. Healthcare providers become suspicious if a cyst grows more than 3 mm (millimeters) in a year. If they’re watching a cyst for changes, they’ll check it every year, two years or five years, depending on how fast it grows.

When should pancreatic cysts be removed?

Some pancreatic cysts may need to be removed if they cause complications or look suspicious for cancer. But pancreatic surgery comes with its own risks and side effects, so healthcare providers consider each cyst carefully. They follow detailed guidelines to determine when they should intervene.

Some of the factors they consider include:

• Size. Cysts that are larger than 3 cm (centimeters) or that appear to be growing faster than usual may need testing for cancer risk. Sometimes large cysts are benign, but they might need removal because they cause discomfort or interfere with your organs.
• Type. Certain types of cysts have a higher risk of becoming cancerous. A healthcare provider might need to remove them right away. Healthcare providers estimate the risk of cancer and weigh it against the risks of surgery for the individual, based on their general health.
• Visual signs. Sometimes, healthcare providers see signs on radiology that suggest a cyst might be cancerous or precancerous. For example, they might notice that your pancreatic duct is enlarged, suggesting a mucinous neoplasm is secreting mucin into the duct. Or they might notice that a cyst has solid parts, suggesting it’s a solid tumor.
• Your condition. Some people have other health conditions or considerations that make pancreatic surgery riskier for them. Healthcare providers weigh these risk factors against your estimated cancer risk.

What is the procedure for pancreatic cyst removal?

If your provider recommends cyst removal, this means surgery. Sometimes, a surgeon can carve out the cyst alone from your pancreas, but more often, they need to take a piece of your pancreas with it. They may even need to take pieces of other nearby organs, due to the location of the cyst.

Possible surgical procedures include:

• Enucleation. This means carving out a solitary cyst from your pancreas without removing the surrounding tissue. You may be a candidate for this relatively minor procedure if you have only one cyst in a precise, accessible location and it doesn’t appear to be cancerous.
• Partial pancreatectomy. This means removing the section of your pancreas containing the cyst or cysts. Your pancreas is roughly fish-shaped, with a “head,” “body” and “tail”. A central pancreatectomy removes the middle section or body of the pancreas. A distal pancreatectomy removes the tail. Due to the close connection between the tail of your pancreas and your spleen, a distal pancreatectomy often involves removing your spleen as well (splenectomy).
• Whipple procedure. The Whipple procedure removes the head of the pancreas and the pancreatic ducts. This is often where mucinous neoplasms are. It’s also a busy intersection between your duodenum (the top of your small intestine), pancreatic duct and common bile duct. Because cancer anywhere in this intersection could spread to the other branches, the Whipple procedure also removes your duodenum and common bile duct, as well as your gallbladder, which attaches to the other end of your common bile duct.
• Total pancreatectomy. A total pancreatectomy means removing your whole pancreas. This might be necessary if you have many cysts that need to be removed, or if you appear to have cancer extensively throughout your pancreas. A total pancreatectomy may also mean removing nearby vessels and organs, including your spleen, gallbladder, duodenum and lower stomach.

What are the risks or side effects of pancreatic cyst surgery?

Surgery on your pancreas can affect its ability to function. You need your pancreas to produce certain digestive enzymes and hormones, including insulin. If too many enzyme-producing or insulin-producing cells are removed during your pancreatectomy, you’ll need lifelong therapies to replace them.

Some pancreatectomy procedures also remove or alter other organs. They can affect your digestive system, your biliary system and your immune system. You may have trouble digesting certain foods and absorbing certain nutrients afterward. If you get a splenectomy, you may get sick more often.

Specific side effects can include:

• Diabetes.
• Exocrine pancreatic insufficiency.
• Fat malabsorption.
• Compromised immunity.

Additional risks of surgery include:

• Bleeding.
• Infections.
• Blood clots.
• Anastomotic leak.

How serious is a pancreatic cyst?

Statistically, a pancreatic cyst is unlikely to cause serious problems. Healthcare providers take pancreatic cysts seriously out of an abundance of caution. They’ll assess your cysts to determine what precautions they should take. While pancreatic surgery is serious, most pancreatic cysts won’t require surgery.

What is the life expectancy after treatment for a pancreatic cyst?

Five-year survival rates after pancreatic cyst surgery are near 100% when the cyst was precancerous or noninvasive. For those with invasive cancer, the five-year survival rate after treatment is approximately 65%-75%, depending on the type of tumor it was. Pancreatic surgery in general has a 4% mortality rate.

What questions should I ask my healthcare provider about my pancreatic cysts?

You might want to ask:

• What type of cysts do I have?
• Are my cysts low risk, medium risk or high risk for cancer?
• How often should I have an imaging scan to check on my cysts?
• Are my cysts growing?