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

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