Pancreatic Pseudocysts

What is a pancreatic pseudocyst?

A pancreatic pseudocyst is a pocket of fluid that develops outside of your pancreas after it’s been injured, usually by pancreatitis. Your pancreas is an organ in your abdomen (belly) that makes enzymes for your digestive system. It delivers these enzymes as fluid to your small intestine through your pancreatic duct.

Pancreatitis is inflammation and swelling in your pancreas. A severe case of pancreatitis can cause your pancreatic duct to leak. When pancreatic juices leak, the digestive enzymes can irritate the surrounding tissues. A protective capsule forms around the leak, made of fibrous, scar-like tissue. This is a pseudocyst.

What’s the difference between a pancreatic cyst vs. a pseudocyst?

A pancreatic pseudocyst isn’t a true cyst because it’s not made of true pancreatic tissue. The capsule is only fibrous scar tissue and doesn’t have the telltale lining of epithelial cells that pancreatic tissue does. Instead, it’s lined with granulation tissue, the type that forms over a wound during the healing process.

A pancreatic pseudocyst is ultimately an inflammatory wound rather than a separate structure. A pancreatic cyst, on the other hand, is a growth in the wall of your pancreas that’s formed from its own tissues. It may contain fluid as well as solid material. Some true cysts have cancerous potential. 

How serious is a pancreatic pseudocyst?

Pancreatic pseudocysts aren’t precancerous and usually don’t cause serious complications. They often go away on their own. But if they grow large, there’s a risk they could interfere with nearby organs or blood vessels. Sometimes, they can become infected. In these cases, healthcare providers intervene.

How common are pancreatic pseudocysts?

Pseudocysts occur in approximately 35% of people with chronic pancreatitis and 10% of people with acute pancreatitis. They’re the most common type of pancreatic mass, accounting for about 75%. But they’re uncommon overall. They affect approximately 3% of adults each year, and rarely children.

What causes a pancreatic pseudocyst?

The most common cause is pancreatitis, and the most common cause of pancreatitis resulting in pseudocysts is alcohol use. Alcohol-related pancreatitis accounts for 70% of pancreatic pseudocysts. Gallstone-related pancreatitis is the second leading cause. In children, it’s more likely to be trauma.

Trauma or swelling from pancreatitis can partially block your pancreatic duct or disconnect it from your intestine. This causes some of the pancreatic fluid to leak out into your abdominal cavity. The fluid collects between the walls of your organs, and a capsule forms around it, creating a pseudocyst.

What are the symptoms of a pancreatic pseudocyst?

Smaller pseudocysts may not cause any symptoms, but larger ones may be noticeable. They may cause symptoms similar to pancreatitis itself. But they usually develop several weeks after the onset of acute pancreatitis, or after a “flare-up” of chronic pancreatitis that disrupted your pancreatic duct.

Symptoms might include:

• Abdominal pain.
• Abdominal swelling.
• Loss of appetite.
• Nausea or vomiting.

Symptoms of complications, if they occur, might include:

• Fever or chills.
• Rising heart rate.
• Dizziness or lightheadedness.
• Jaundice.

What are the possible complications of a pancreatic pseudocyst?

Complications are unlikely but possible, including:

• Infection. While most pseudocysts mainly contain pancreatic fluid, some may also contain bits of dead tissue. This puts them at risk of infection, as roaming bacteria like to eat dead tissue. An infected pseudocyst can be especially dangerous if it ruptures. While this is rare, it would allow the infection to escape into your abdominal cavity, where it could become septic.
• Vessel compression. A large pseudocyst could potentially compress a nearby blood vessel or bile duct. This could partially block the blood flow or bile flow through those vessels. A pseudocyst could also compress and further disrupt your pancreatic duct, causing further complications.
• Gastrointestinal obstruction. A large pseudocyst could compress and obstruct your stomach or small intestine, preventing food from passing through. You might be unable to eat or poop.
• Hemorrhage. A pseudocyst rubbing up against a blood vessel could potentially erode through the vessel wall, causing a bleed. If the vessel bleeds into the pseudocyst, the pseudocyst could rupture.

How do healthcare providers diagnose pancreatic pseudocysts?

Healthcare providers can usually recognize pancreatic pseudocysts on a high-quality imaging test, like a contrast CT scan or MRI. But sometimes, they need to take a sample to distinguish a pseudocyst from another type of mass. They can do this with endoscopic ultrasound and fine needle aspiration.

Endoscopic ultrasound

Endoscopic ultrasound combines endoscopy with ultrasound. A healthcare provider passes a tiny camera on a long tube (endoscope) down your throat and into your small intestine. Then, they pass a smaller tube with an ultrasound wand on the end through the endoscope to visualize your pancreas.

Fine needle aspiration

Fine needle aspiration is a type of biopsy procedure. An endoscopist can pass tiny tools through the endoscope to perform minor procedures, including biopsy. They can pass a fine, hollow needle through to take fluid and tissue samples of the pseudocyst. They’ll send these samples to a lab to analyze.

What do pancreatic pseudocysts look like in imaging?

Your pancreas is roughly fish-shaped, with a head, body and tail. About two-thirds of pseudocysts occur at the tail, and one-third at the head. Pseudocysts are roundish and smooth, with well-defined walls and filled with clear, watery fluid. They vary in size from 2 to 30 centimeters in diameter. You might have one or several.

How do healthcare providers treat pancreatic pseudocysts?

Many pancreatic pseudocysts resolve on their own with time. Healthcare providers monitor them while offering supportive care, such as:

• Pain relief.
• IV fluids.
• Nutrition (through a tube or an IV).

When pseudocysts don’t go away or show signs of complications, healthcare providers intervene.

How long does it take for a pancreatic pseudocyst to go away?

Healthcare providers intervene when pseudocysts last longer than six weeks. About one-third of them will go away on their own during this time. They may be less likely to resolve on their own if you have multiple pseudocysts or if you have long-term complications from chronic pancreatitis, like scarring.

What is the treatment for a complicated or high-risk pseudocyst?

Healthcare providers drain pseudocysts to make them go away. They can do this in a few different ways. Endoscopic drainage is usually the first choice, although certain cases might call for other methods, like surgery. Endoscopic drainage is less invasive and has similar long-term success rates to surgery.

Cystogastrostomy

The standard procedure is called a cystogastrostomy, which means creating a connection between the pseudocyst and your stomach for the pseudocyst to drain into. Depending on where the pseudocyst is located, it might be a connection to your small intestine instead, or even your pancreatic duct.

Your stomach and small intestine are well-equipped to process the fluid from the pseudocyst. Both have a protective lining that insulates them from digestive enzymes and acids. (Your small intestine is where pancreatic fluids are usually delivered.) Once the fluid has been drained, the capsule will dissolve.

What can I expect from treatment for a pancreatic pseudocyst?

Treatment for a pancreatic pseudocyst will require a brief hospital stay and a follow-up procedure several weeks later to remove the stents or drainage tubes they used to keep the cystogastrostomy open. The success rate of drainage procedures is over 90%. Occasionally, pseudocysts come back.

When should I see a healthcare provider about a pancreatic pseudocyst?

See a healthcare provider if you have symptoms of pancreatitis: Abdominal pain that spreads to your back, combined with nausea and/or vomiting. If you’ve recently been treated for pancreatitis and you develop symptoms again four to six weeks later, you might have developed a pancreatic pseudocyst.