A pancreatic pseudocyst is a collection of tissue and fluids that forms on your pancreas, an organ located behind your stomach. It is usually the result of pancreatitis (inflammation of the pancreas) or a hard blow to your abdomen.
Pseudo means “false.” A pseudocyst is shaped like a cyst but is made from different kinds of tissue than a true cyst. A true cyst is more likely to be cancerous than a pseudocyst.
A pancreatic pseudocyst is usually not dangerous unless it ruptures. A ruptured pancreatic pseudocyst, on the other hand, is a life-threatening condition. If you experience any of the following symptoms, go to an emergency room, or call 911:
- high, persistent fever
- severe pain in your upper stomach, with pain radiating to your back
- vomiting blood
- weak, rapid heartbeat
Pay especially close attention to these symptoms if you have pancreatitis in your personal or family medical history.
What Causes a Pancreatic Pseudocyst?
Pancreatic pseudocysts most often follow a bout of pancreatitis. Pancreatitis is a serious and painful condition in which pancreatic enzymes, which help you digest fats and sugars, overreact and begin to digest the tissues of the pancreas itself.
This can cause swelling, bleeding, and damage to the tissues and blood vessels in the pancreas. Cysts typically form when the ducts that carry pancreatic juices to the intestine become blocked.
There are two types of pancreatitis: acute and chronic. Acute pancreatitis is sudden and can go away without treatment. Chronic pancreatitis resists treatment.
Causes of Pancreatitis
While pancreatitis may be a complication of surgery or caused by certain autoimmune disorders, alcoholism is the most common cause for this condition.
According to the National Center for Biotechnology Information, 70 percent of pancreatitis cases in the U.S. are caused by alcoholism or alcohol abuse (NCBI, 2010).
Additionally, alcoholism can raise the level of certain fats (triglycerides) in your bloodstream. Your pancreas helps your body digest fats, but it can become damaged if there is too much fat to process.
Your triglyceride level can also be higher-than-normal because of too much fat and cholesterol in your diet, or because you have diabetes or kidney disease.
Pancreatitis can also be caused by gallstones. These are pebble-like deposits that develop in the gallbladder, a small organ located near the pancreas that stores bile produced in the liver.
Gallstones may be very small, or can grow as large as a golf ball. In some cases, they may block the ducts that drain the pancreas, causing pancreatitis to develop.
What are the symptoms of pancreatic cysts?
The symptoms of pancreatic cysts depend on their size and location. Small (less than two cm) cysts usually cause no symptoms.
Large pancreatic cysts can cause abdominal pain and back pain presumably by exerting pressure on the surrounding tissues and nerves.
Small or large cysts in the head of the pancreas also may cause jaundice (yellowing of the skin and eyes with darkening of the urine) due to obstruction of the common bile duct.
(Obstruction causes bile to back up and forces bilirubin–the chemical that produces jaundice–back into the bloodstream and forces it to be excreted in the urine.)
If the cysts become infected, it may result in fever, chills, and sepsis.
On rare occasions, large pseudocysts can compress the stomach or the duodenum leading to obstruction to the movement of food in the intestines, resulting in abdominal pain and vomiting.
If a cyst becomes malignant and begins to invade the surrounding tissues, it may lead to the same type of pain as pancreatic cancer, pain that usually is constant and felt in the back and upper abdomen.
How are pancreatic cysts diagnosed?
Since the majority of pancreatic cysts are small and produce no symptoms, they often are discovered incidentally when abdominal scans (ultrasound [US], computerized tomography or CT, magnetic resonance imaging or MRI) are performed to investigate unrelated symptoms.
Unfortunately, ultrasound, CT, and MRI cannot reliably distinguish benign cysts (cysts that usually need no treatment) from precancerous and cancerous cysts (cysts that usually require surgical removal).
Endoscopic ultrasound (EUS) is becoming increasingly useful in determining whether a pancreatic cyst is likely to be benign, precancerous, or cancerous.
During endoscopic ultrasound, an endoscope with a small ultrasound transducer at its tip is inserted through the mouth, esophagus, and stomach into the duodenum.
From this location, which is very close to the pancreas, liver, and gallbladder, accurate and detailed images can be obtained of the liver, pancreas and the gallbladder.
During endoscopic ultrasound, fluid from cysts and samples of tissue also can be obtained by passing special needles through the endoscope and into the cysts.
The process of obtaining tissue or fluid with a thin needle is called fine needle aspiration (FNA).
The fluid obtained by FNA can be analyzed for cancerous cells (cytology), amylase content, and for tumor markers.
Tumor markers, such as CEA (carcinoembryonic antigen), are proteins produced in large quantities by cancer cells.
For example, pancreatic pseudocyst fluid will typically have high amylase levels but low CEA levels.
A benign serous cyst adenoma will have low amylase and low CEA levels, whereas a precancerous or cancerous mucinous cyst adenoma will have low amylase levels but high CEA levels.
Most recently, DNA from cells that are aspirated from the cyst has been analyzed for changes suggestive of cancer.
The risks of endoscopic ultrasound and fine needle aspiration are small and consist of a very small incidence of bleeding and infection.
Occasionally, it is difficult even with the diagnostic tools of endoscopic ultrasound and fine needle aspiration to determine if a pancreatic cyst is cancerous or precancerous.
If the answer is not clear, sometimes repeated endoscopic ultrasound and aspiration are done if the suspicion for cancer or precancer is high.
In other cases, the cyst is reexamined by CT, MRI, or even endoscopic ultrasound after a few months to detect changes that more strongly suggest that cancer has developed. In still others, surgery is recommended.
What Treatments Are Available?
If your doctor determines that you have a pseudocyst, but you don’t have any symptoms, he or she may suggest you wait to see if the cyst goes away on its own.
The growth or shrinking of the cyst can be monitored with regular imaging tests.
When a pseudocyst is pressing on other organs, it should be drained to reduce its size. It should also be drained if it’s grown so large that it could rupture.
Drainage requires surgery under general anesthesia, meaning that you will be asleep and pain-free during the procedure.
Surgery involves making a very small incision to drain the pseudocyst with a needle guided by ultrasound or an endoscopic camera.
Alternatively, the doctor might make a larger incision to view the pseudocyst directly.
The contents of the pseudocyst will be drained or suctioned out. A sample of the contents will be sent to a lab to test for infections and signs of cancer.
You will be prescribed antibiotics even if you don’t have an infection, to make sure one doesn’t develop.
What Is the Outlook for Someone With a Pancreatic Pseudocyst?
The outlook for someone who has a pseudocyst is usually good, as long as there is no chance of rupture. Surgery to drain pseudocysts has a high recovery rate.
What Can I Do to Prevent a Pancreatic Pseudcyst?
Pancreatitis is the most common cause of pseudocysts, so preventing pancreatitis is the best way to prevent cysts from forming.
If you drink alcohol regularly or are an alcoholic, consider stopping or seeking out treatment for addiction, especially if you have a family history of alcoholism or pancreatitis.
A diet low in carbohydrates and cholesterol, and consisting of fresh fruits, fresh vegetables, and lean protein, can lower your triglycerides and help prevent the development of pseudocysts.