Pancreatic cysts are abnormal, sac-like pockets of fluid on or within your pancreas. Though it may be alarming to learn you have a pancreatic cyst, the good news is that most pancreatic cysts aren't cancerous — and many don't even cause symptoms.

In fact, many pancreatic cysts aren't technically cysts at all. Called pseudocysts, these pockets of fluids aren't lined with the type of cells found in true cysts. Instead, a pseudocyst's walls may include cells normally found in other organs, such as the stomach, intestines and the pancreas itself. Pseudocysts are never cancerous.

Your doctor may want to take a sample of the pancreatic cyst fluid to determine whether it's malignant or benign. If your cyst is or can become cancerous, treatment involves surgical removal.

You may have pancreatic cysts, including pseudocysts, but experience no symptoms. When signs or symptoms do occur, they typically include:

• Persistent abdominal pain, which may radiate to your back
• A mass you can feel in your upper abdomen, where your pancreas is located
• Nausea and vomiting

When to see a doctor
Cysts can become infected, so see a doctor if you are feverish and have persistent abdominal pain.

A ruptured pseudocyst is a medical emergency. Fluid in the cyst contains enzymes activated for digestion. When a cyst ruptures, the released fluid can damage nearby blood vessels and cause massive bleeding. Seek emergency medical treatment if you have signs or symptoms of internal bleeding and shock, including:

• Fainting
• Severe abdominal pain
• Decreased consciousness
• Rapid heartbeat

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Location of pancreas

In many cases, the cause of a particular pancreatic cyst is unknown. Some cysts are associated with rare illnesses — such as von Hippel-Lindau disease, which is a genetic disorder that can affect the brain, retina, adrenal glands, kidneys and pancreas.

Pseudocysts often follow a bout of pancreatitis, a painful condition in which the pancreas's digestive enzymes become prematurely active and digest some of the pancreas itself. Pseudocysts can also result from blunt trauma to the abdomen, such as during a car accident.

Heavy alcohol use and gallstones are risk factors for pancreatitis, and pancreatitis is a risk factor for pseudocysts — the most common type of pancreatic cyst.

Many pancreatic cysts are discovered during abdominal scans for other problems. However, if the signs and symptoms of pancreatic cysts cause you to make an appointment with your doctor, there are some things you can do to prepare for your appointment.

What you can do

• Write down any symptoms you're experiencing. Include those that may seem to be related to pancreatic cysts, as well as any symptoms that may seem unrelated to the reason for which you scheduled the appointment.
• Write down questions to ask your doctor. Preparing a list of questions ahead of time will help you make the most of the limited time you have at your appointment.

What to expect from your doctor
Your doctor is likely to ask you questions about your symptoms, such as how long you've been experiencing them and the location and severity of any abdominal pain. Think about how you'll answer these questions before you arrive.

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Types of pancreatic cysts

Pancreatic cysts are diagnosed more often now than in the past, but not because more people have them. Instead, improved imaging technology has made pancreatic cysts easier to find. In fact, many pancreatic cysts are found during abdominal scans for other problems.

Most pancreatic cysts can be detected by ultrasound, computerized tomography (CT) or magnetic resonance imaging (MRI) scans. Your doctor may also order an endoscopic ultrasound to visualize the cyst and to obtain fluid from the cyst for analysis. In this study, a thin flexible tube (endoscope) is passed through your mouth and into your stomach and upper small intestine. The endoscope is equipped with a small ultrasound probe to image the cyst and with a needle to obtain fluid from the cyst.

Although the majority of pancreatic cysts are benign pseudocysts, doctors may suspect another type of cyst if it occurs with no previous history of pancreatitis or abdominal injury or if it has internal walls.

In some cases, the location of the cyst in your pancreas — along with your age and sex — can help doctors pinpoint what type of cyst you have.

• Mucinous cystadenoma. These cysts are usually located in the body or tail of the pancreas and occur most often in middle-aged women. They are precancerous, and some may already be cancerous when discovered. Larger cysts are more likely to be cancerous.
• Mucinous duct ectasia. More common in men, these cysts consist of dilated ductal segments, usually within the head of the pancreas. Also known as intraductal papillary mucinous neoplasms, these growths are often cancerous.
• Serous cystadenoma. These growths can become large enough to displace nearby organs, causing such symptoms as abdominal pain and a feeling of fullness. They occur most frequently in middle-aged women and become cancerous only rarely.
• Papillary cystic tumor. The least common of the nonpseudocysts, papillary cystic tumors — also known as papillary cystic neoplasm or solid and pseudopapillary neoplasm — occur most often in young women and are usually located in the body or tail of the pancreas. They are usually cancerous.

Islet cell tumors, also known as neuroendocrine tumors, are less common. Normally, the pancreas's islet cells produce insulin and other hormones. Islet cell tumors can also produce these hormones.

Treatment differs depending on the type of cyst and whether it causes symptoms. Sometimes, no treatment is necessary.

A benign pseudocyst — even a large one — can be left alone as long as it isn't causing you worrisome symptoms or enlarging. A pseudocyst that is causing bothersome symptoms or growing larger may be drained with a needle or surgically removed, often with the use of an endoscope.

Because a serous cystadenoma so rarely evolves into cancer, it also can be left alone unless it causes symptoms or enlarges. Your doctor may want to follow its size over time by checking repeat scans, especially if a precancerous cyst can't be ruled out.

Surgery
Treatment for most other types of lesions in the pancreas is surgical removal, because of the risk of cancer. Surgery is very effective, with little chance of recurrence. However, a pseudocyst that is removed may recur if you have ongoing pancreatitis.

The best way to avoid pseudocysts is to avoid pancreatitis, which is usually caused by gallstones or heavy use of alcohol. If your pancreatitis is due to alcohol abuse, you need to abstain from alcohol. If gallstones are triggering pancreatitis, you may need to have your gallbladder removed.