Pancreatic Pseudocysts

Snapshot

• A 42-year-old man with a history of alcohol abuse presents to the clinic with complaints of constant pain at the abdominal region. A physical examination demonstrates a 3-cm mass at the epigastric region. Further laboratory testing shows a persistently elevated serum and urine amylase.

Introduction

• Clinical definition
  • describes a circumscribed collection of fluid containing pancreatic enzymes, blood, and necrotic tissue occurring outside the pancreas
    • the capsule is a nonepithelialized wall consisting of fibrous granulation tissue
    • usually develops within several weeks after the onset of pancreatitis
• Epidemiology
  • demographics
    • accounts for approximately 75% of all pancreatic masses
    • male predominance, which mirrors the demographic distrubtion seen in pancreatitis
• Pathogenesis
  • most commonly occurs following acute pancreatitis and abdominal trauma but can also occur due to chronic pancreatitis
    • abdominal trauma is the more common cause in children
  • can also be single or multiple, though multiple cysts are more frequently seen in patients with alcoholism
  • the condition seems to stem from disruptions of the pancreatic duct
    • occurs due to pancreatitis and/or extravasation of enzymatic material 
• Associated conditions
  • acute pancreatitis
    • alcoholism
    • gallstone
  • chronic pancreatitis
• abdominal trauma

Presentation

• Symptoms
  • abdominal pain
    • usually with a history of pancreatitis
  • anorexia
  • indigestion
  • nausea
• Physical exam
  • abdominal mass 
  • tender abdomen
  • fever
  • scleral icterus
  • pleural effusion
  • peritoneal signs
• if cyst rupture or infection

Imaging 

• Abdominal computed tomography (CT) with contrast 
  • preferred diagnostic test
  • positive findings include a well-circumscribed fluid collection that is typically extra-pancreatic with homogenous fluid density with no internal septae
• Magnetic resonance imaging (MRI)
  • more sensitive test compared to CT
  • allows for better differentiation between pancreatic pseudocyst and other diagnosis (e.g., pseudoaneurysm)
• Endoscopic ultrasound (EUS)
  • indicated in patients where the imaging findings or clinical setting is unclear/atypical
  • can assess for features suggestive of a cystic neoplasm (e.g., internal septations)
• allows for treatment planning

Studies 

• Serum amylase and lipase
  • may be normal or elevated
• Serum bilirubin and liver function tests
  • may be elevated if there is involvement of the biliary tree
• Cystic fluid analysis
  • low levels of carcinoembryonic antigen (CEA) and CEA-125
  • low fluid viscosity
• high amylase

Differential 

• Cystic neoplasm
  • differentiating factors
    • MRI can often differentiate between pseudocyst and cystic neoplasm; if the diagnosis is still uncertain, EUS and fine-needle aspiration of the fluid can be performed
• cystic fluid analysis will demonstrate high CEA-125, high fluid viscosity, and low amylase

Treatment

• Most pseudocysts resolve without interference and require only supportive care
• First-line
  • observation with follow-up imaging every 3-6 weeks
  • supportive care
    • nasogastric feeding if needed for pain relief
    • proton pump inhibitor
    • octreotide to reduce pancreatic secretions
• Second-line
  • drainage of the pseudocyst is indicated in patients who are symptomatic, have rapidly enlarging pseudocysts, or have complications (e.g., infection of the cyst)
  • endoscopic drainage
    • preferred method of drainage
    • complications include bleeding, performation, and secondary infection
  • percutaneous catheter drainage
    • higher morbidity, longer hospital stays, and longer duration of indwelling drains compared to endoscopic drainage
• Third-line
  • surgery
• indicated in patients with infected pancreatic necrosis and symptomatic sterile necrosis

Complications

• Bleeding/hemorrhage
  • erosion of the pseudocyst into a vessel
• GI obstruction
• Pseudocyst rupture
• Peritonitis