Pseudocysten

Pseudocysts are fluid-filled collections that resemble cysts but lack a true epithelial lining. The term most often refers to pancreatic pseudocysts, which are collections of pancreatic fluid surrounded by a fibrous wall rather than a true cyst lining. They typically develop after an episode of pancreatitis (acute or chronic) or pancreatic trauma, when pancreatic fluids leak and become walled off by surrounding tissue.

Most pancreatic pseudocysts form in the lesser sac or around the pancreas, but they can extend into adjacent spaces. The cavity is lined not by epithelium but by granulation tissue and fibrous tissue. The contents usually consist of pancreatic enzymes, inflammatory cells, and debris. They may remain stable, gradually enlarge, become infected, rupture, or cause compression of surrounding structures.

Clinical presentation varies. Some pseudocysts are asymptomatic and found incidentally, while others cause abdominal pain, fullness, nausea, vomiting, or early satiety. Larger cysts can compress the stomach, bile ducts, or intestinal segments, leading to jaundice or gastric outlet obstruction. Diagnosis relies on imaging such as ultrasound, contrast-enhanced computed tomography (CT), and magnetic resonance imaging (MRI). Endoscopic ultrasound (EUS) can aid in characterization and planning drainage. Cyst fluid analysis may show elevated amylase; cytology and tumor markers help exclude cystic neoplasms when needed.

Management depends on size, symptoms, and complications. Small, asymptomatic pseudocysts may be observed with supportive care. Indications for intervention include symptoms, infection, rupture, hemorrhage, or growth. Drainage options include endoscopic transmural drainage (creating a tract to the stomach or duodenum), percutaneous catheter drainage, or surgical drainage (cystogastrostomy, cystojejunostomy). Addressing the underlying pancreatitis is also important. Prognosis is generally favorable with appropriate treatment, though complications can occur.