The pancreas is an organ positioned behind the stomach that produces hormones like insulin to regulate blood sugar and generates digestive enzymes. When the pancreas becomes inflamed, a condition known as pancreatitis, it can lead to complications. One such complication is the formation of a pancreatic pseudocyst, a collection of fluid that develops near the organ.
What Exactly is a Pancreatic Pseudocyst
A pancreatic pseudocyst is a localized fluid collection rich in pancreatic enzymes, blood, and other fluids, forming in or around the pancreas. These collections vary significantly in size, often ranging from a few centimeters to more than 10 centimeters in diameter. They are frequently located adjacent to the pancreas, sometimes in the lesser sac behind the stomach.
The structure is not considered a true cyst, which is why the term “pseudo” is used. A true cyst possesses a distinct, internal lining of epithelial cells, a feature the pseudocyst wall lacks. Instead, the pseudocyst is encapsulated by a layer of fibrous and granulation tissue that forms in response to inflammation.
The fluid contents are highly concentrated with digestive enzymes, such as amylase and lipase, which have leaked from the damaged pancreatic duct. This collection takes time to organize, typically forming a well-defined fibrous wall approximately four to six weeks following the initial damage. This wall contains the fluid, separating it from the rest of the abdominal cavity.
Why Do They Form
The underlying mechanism for pseudocyst formation is the leakage of pancreatic juice and enzymes from a damaged ductal system into the surrounding tissues. This leakage most commonly occurs as a complication following acute pancreatitis or as a feature of chronic pancreatitis. When pancreatic enzymes escape the duct, they begin to irritate and digest the nearby tissue.
The majority of pseudocysts are linked to pancreatitis caused by factors such as excessive alcohol consumption or gallstones obstructing the bile duct. Severe inflammation increases pressure within the ducts, which can lead to rupture or disruption. The body’s inflammatory response then attempts to wall off the leaked fluid, resulting in the formation of the fibrous capsule.
While pancreatitis is the most frequent precursor, pseudocysts can also develop following significant abdominal trauma that causes direct injury to the pancreas or its duct. This injury allows pancreatic fluid to escape, triggering the same inflammatory containment response. In children, abdominal trauma is a more common cause compared to adults.
What Symptoms Should I Look For
A pancreatic pseudocyst can produce a range of symptoms, or remain completely asymptomatic, particularly if the collection is small. The most common complaint is persistent or severe abdominal pain, which often radiates to the back. Patients may also experience abdominal fullness or bloating.
Other frequent symptoms include nausea, vomiting, and a noticeable loss of appetite, which can lead to unexplained weight loss. If the pseudocyst grows large enough, a physician may detect a palpable mass during a physical examination. These symptoms generally develop several weeks after the initial episode of pancreatitis.
More severe symptoms indicate a complication, such as the pseudocyst pressing on adjacent organs or blood vessels. Compression of the bile duct can cause jaundice, a yellowing of the skin and eyes. Pressure on the stomach or small intestine can lead to difficulty eating or digesting food. A sudden worsening of pain, fever, or signs of infection require immediate medical attention, as they can signal a rupture or internal bleeding.
How Doctors Confirm and Treat the Condition
Diagnosis typically begins with a review of the patient’s history of pancreatitis and a physical examination. Imaging studies are then used to confirm the presence, size, and location of the fluid collection. The preferred initial imaging method is often a contrast-enhanced Computed Tomography (CT) scan, which clearly visualizes the well-defined, fluid-filled mass near the pancreas.
Magnetic Resonance Imaging (MRI) and Endoscopic Ultrasound (EUS) are also utilized. These offer detailed images that help differentiate a pseudocyst from other cystic lesions, such as those that might be cancerous. In complex cases, EUS can guide a fine needle to sample the fluid, which is then analyzed for high levels of pancreatic enzymes like amylase.
Management begins with watchful waiting for small, asymptomatic collections. Many pseudocysts, particularly those under six centimeters, resolve spontaneously without intervention. If the pseudocyst is large, causes persistent symptoms, or has not resolved after six weeks, drainage is usually recommended.
The most common interventional approach is endoscopic drainage, a minimally invasive procedure. This uses an endoscope guided by EUS to create a connection between the pseudocyst and the stomach or small intestine, allowing the fluid to drain internally. Alternatively, a percutaneous drainage catheter can be placed through the skin and into the cyst, a method often favored if the collection is infected.
Surgical drainage, such as a cyst-jejunostomy, involves creating a permanent connection between the cyst and a loop of the small intestine for continuous internal drainage. While surgery was historically the standard, it is now typically reserved for cases where endoscopic drainage has failed or when the cyst is anatomically complex. The choice of treatment depends heavily on the size, symptoms, and communication of the pseudocyst with the pancreatic duct.