This page was reviewed under our medical and editorial policy by
Toufic Kachaamy, MD, Chief of Medicine, City of Hope Phoenix
This page was reviewed on May 26, 2023.
A cyst is by definition a hollow growth, but it can be filled with fluid, including pus, solid “cheesy” or chunky matter, or even air. These closed, sac-like pockets of tissue can happen anywhere in the body. Cysts that develop in the pancreas are called pancreatic cysts.
While these cysts may sound alarming, they’re often benign. More than 90 percent of pancreatic cysts are not cancerous, although some may be considered pre-cancerous. Pancreatic cysts are unlikely to cause serious health issues and often are found while taking images of the abdomen for another reason. However, sometimes they cause symptoms or develop into a more dangerous condition, including cancer. Having a lot of cysts may be a sign of a specific medical syndrome that could increase the risk for pancreatic and other cancers.
Some genetic mutations that lead to the development of pancreatic cysts also increase cancer risk. These are called hereditary cancer syndromes. Almost all pancreatic cysts below 15 mm in size are not cancerous. How much they increase the risk of cancer and in which organs these cancers are typically found are listed below.
For example, kidney, pancreatic and other cysts are a symptom of the genetic von Hippel-Lindau syndrome (VHL). People with VHL are at a higher-than-normal risk for tumors in multiple organs, including the eyes, as well as in blood vessels of the nervous system, and for developing kidney cancer and pancreatic cancer.
The seriousness of pancreatic cysts varies dramatically, with some more prone to becoming cancerous than others. Most pancreatic cysts grow slowly--between 3mm and 6mm per year. Faster growing cysts may indicate they are at a higher risk of developing into cancer.
The most common types of cysts found in the pancreas are those caused by injury or inflammation. These include pseudocysts, paraduodenal wall cysts and infection-related cysts. Inflammation-related cysts are a common complication of pancreatitis, a condition in which the pancreas has become inflamed. These cysts are noncancerous (benign).
Other types of benign pancreatic cysts include:
Intraductal papillary mucinous neoplasms (IPMNs) are cysts that grow in the ducts of the pancreas. They were thought to be rare, but in recent years researchers have found they make up about 20 percent of cystic lesions in the pancreas, according to a study published in the Archives of Pathology & Laboratory Medicine. That same study notes that IPMNs that block the main pancreatic duct are more likely to turn cancerous than those blocking a branching duct. Even when benign, they can cause symptoms if they’re blocking the flow of digestive juices through the pancreatic ducts, and they may require treatment.
Mucinous cystic neoplasms (MCNs), sometimes called mucinous cystadenomas, are cysts filled with a jelly-like fluid called mucin. MCNs are far more common in women than in men and tend to develop in midlife, in the late 40s just before the start of menopause. While they’re typically benign and slow-growing, they can become cancerous if left untreated. Less than 20 percent of MCNs are cancerous, according to the Archives of Pathology & Laboratory Medicine.
Also known as SPNs, these are rare tumors once thought to be cysts. Doctors now know an SPN is a type of tumor with a cyst-like appearance. SPNs are far more likely to affect women than men, usually in their 20s or 30s. They’re typically slow-growing but have the ability to spread to other organs, such as the liver or peritoneum, if they’re not removed. Even if an SPN has spread, surgery can be successful at removing it.
Serous cystic neoplasms, or SCNs (also known as serous cystadenomas), are a type of tumor. The name comes from the honeycomb-like network of serous-filled cysts found within it. SCNs are for the most part benign. However, even when it’s benign, if an SCN begins to cause symptoms, the patient will want to have it treated.
Injuries and pancreatitis are the most common causes of pancreatic cysts. Pancreatitis can develop from a disease such as alcoholism, from having a gallstone lodge in a duct, or from trauma. Rarely, pancreatic cysts can be caused by an infection such as tuberculosis, tapeworms or other organisms. Some pancreatic cysts are linked to polycystic kidney disease, medullary cystic kidneys or cystic fibrosis.
Pancreatic cysts are also associated with certain rare inherited and/or congenital syndromes (conditions the patient is born with). These include:
Many pancreatic cysts have no symptoms and are discovered accidentally when the patient is undergoing tests for another reason. As tests such as magnetic resonance imaging (MRI) scans have become more commonplace, more pancreatic cysts are being detected.
When symptoms do occur, they can feel like vague abdominal discomfort. If a pancreatic cyst blocks any of the pancreatic ducts, it can affect digestion. If the cyst grows large enough, it may impact the functioning of the pancreas. The patient may notice:
Pancreatic cysts are detected with imaging studies, such as computed tomography (CT) and MRI scans. The patient's doctor may also decide to perform an endoscopic ultrasound procedure. This involves inserting a lighted tube, or endoscope, with a camera attached through the patient's mouth and down his or her digestive tract to the pancreas. The camera relays images to a monitor.
A tissue sample, called a biopsy, as well as a fluid sample from the cyst, may be taken to determine the exact type of cyst. The sample is sent to a laboratory, where a pathologist analyzes the cells and makes a determination about whether the cyst is benign, malignant or precancerous. Genetic testing for any inherited syndromes may be performed to get more information to guide treatment.
In most cases, a gastroenterologist will treat pancreatic cysts.
Depending on the type of cyst, the doctor may: