Pancreatic cysts: What they are and how they’re treated
The pancreas is part of the digestive system which helps your body regulate blood sugar and digest food. Sometimes cysts can develop inside the pancreas. These small, fluid-filled sacs usually don’t cause any symptoms, and most people don’t even realize they have them.
“About 10% to 20% of people over the age of 60 have pancreas cysts,” says surgical oncologist Michael Kim, M.D. Most of these are benign and will never cause problems.
Although most cysts don’t cause symptoms, there are some signs to watch for. These include nausea, vomiting, abdominal bloating and pain in the abdomen.
“If you experience any of these symptoms without relief for more than two weeks, you should talk to your doctor,” Kim says.
How a pancreas cyst diagnosis is made
Most of the time, pancreatic cysts are found during medical treatment for other conditions. “You may experience back pain and go to the emergency room,” Kim says. “Or, if you get a CT scan after an injury, your care team may find cysts that way,” he adds.
If you have pancreatic cysts, your care team will also look at the size of the cyst. “Cysts smaller than 2 centimeters usually don’t require treatment, unless they’re causing pain or other symptoms,” Kim says.
Your care team will also look to see if you have any of the following:
Dilation of the main duct of the pancreas
Nodules inside the cyst
Enhancement of the cyst walls during an IV contrast test
Your care team will likely perform a biopsy to learn about features and the type of cyst if you have any of these risk factors.
Looking for a genetic link to pancreatic cysts
After a biopsy, fluid from inside the cyst may be sent for genetic sequencing.
There are two main genes associated with cysts in the pancreas: KRAS and GNAS. Kim says other genes associated with higher cancer risk, like BRCA mutations, can also play a role in cyst development.
“We’re not sure why some people have cysts that develop into cancer and some don’t,” Kim says. That’s why he and his team are working to better understand the genetic link between pancreatic cysts and cancer.
Types of pancreatic cysts
There are several types of pancreatic cysts. Some are more likely to develop into cancer than others.
Intraductal Papillary Mucinous Neoplasms (IPMNs) are the most common type of cyst found in the pancreas. These are also divided into different categories depending on where they’re found within the system of ducts that helps the pancreas secrete digestive enzymes.
Main duct IPMNs are the most likely to become cancerous and are found in the main duct to the pancreas.
Side branch IPMNs are most common and are found in the branches off the main duct.
Mixed IPMNs can be found in both the side branches and the main duct.
Mucinous cystic neoplasms tend to develop in younger healthy women. These typically develop inside the pancreas, not in the ducts.
Solid pseudo papillary neoplasms may look like cysts, but they’re solid masses made up of cells.
Serous cystadenomas are benign but can sometimes become quite large and need to be removed.
Pseudo cysts are benign and caused by inflammatory responses in the pancreas. These generally don’t cause problems unless they’re very large and cause symptoms.
Pancreatic cyst treatment options
For most pancreatic cysts, surveillance is a good option. “We can watch cysts through routine scans for a long time,” Kim says.
Cysts that are cancerous or pre-cancerous are most commonly treated with surgery, depending on the patient’s age and risk factors. “We can take out the cyst, as well as the part of the pancreas where it was found, to reduce the risk of cancer growing or spreading,” Kim says.
The exact type of surgery will depend on the cyst’s location.
If the cyst is located in the head of the pancreas, patients will undergo a type of surgery called the Whipple procedure.
A procedure called a distal pancreatectomy is used to remove cysts located in other parts of the pancreas. Talk to your care team about which treatment is right for you.
“It’s important to seek care at a center like MD Anderson that has specialized expertise in diagnosing and treating pancreatic cysts,” Kim says.
New research focuses on pancreatic cyst prevention and growth
“If we can get the immune system to attack antigens on the surface of problematic cysts, we could potentially keep them from growing, or get rid of them altogether,” Kim says.
Kim credits the volume of patients MD Anderson sees with the ability to build upon clinical trial data. “We're in a position where we can make our guidelines for informing our practices, based on the results we’ve seen so far,” he says.