Cystic Disease of the Pancreas

(Surgical Oncology 2005;14:155-78. Pancreas 2002;25:217-21)

DEFINITION:

True pancreatic cyst has epithelia cell lining (account for only 10-15% of all cystic lesions of the pancreas)
Pancreatic pseudocyst is lined only by inflammatory tissue, it has no epithelium; Communicates with pancreatic duct (PD), so has high Amylase levels in fluid
- Spontaneous resolution: 30%; Less likely with chronic pancreatitis or if developed as a consequence of trauma
Acute fluid collections occur within 4 wks of pancreatitis, no well-defined wall and irregular, no communication to PD, low amylase content in fluid
- Spontaneous resolution: 65%
Hemosuccus Pancreaticus is major bleeding into the main PD from a pseudoaneurysm
- Angiography is diagnostic/therapeutic; Rarely surgery

EPIDEMIOLOGY:

Pancreatic cysts occur in up to 25% of patients undergoing abdominal imaging
- Increasing resolution of CT and MRI allows detection of cysts less than 2 cm in size
The prevalence increases with age

ETIOLOGIES: Differential of lesions of the pancreas:

Pancreatic pseudocyst (70-90%):

Def:	See Definition above; Often occur after episodes of acute or chronic pancreatitis Often contain inflammatory cells (PMN, leukocytes) with no evidence of mucin or epithelial cells
Clinical:	Frequently (not invariably) associated with pain; Large cyst can compress adjacent structures (early satiety, jaundice)
Labs:	↓ > ↑ CEA, ↓ > ↑ CA 72-4, ↑ CA19-9, ↓ CA125, ↓ CA15-3, ↑ Amylase Fluid characteristics: thin, dark/muddy, nonmucinous, opaque
Dx:	See Diagnostic Studies below; EUS: anechoic (black), thick walled, rare septations
Tx:	See Treatments below

Cystic Neoplasms (10-15%): Benign or Malignant terminology

Serous cystic neoplasms (SCN) (32-39%): Serous Cystadenoma or Serous Cystadenocarcinoma

Def:	Numerous small cyst filled with glycogen-rich (+PAS), low viscosity serous fluid, cuboidal epithelium lined Equal distribution throughout pancreas
Clinical:	Benign tumors, ♀ > ♂, Average age at diagnosis is 50-60; May be associated with gene for von Hippel-Lindau disease
Labs:	↓ CEA (<5 ng/ml), ↓ CA 72-4, ↓↑ CA19-9, ↓ CA125, ↓ CA15-3, ↓ Amylase Fluid characteristics: thin, clear, nonmucinous, bloody
Dx:	CT/MRI/EUS: “Honeycomb with sunburst calcification in a central fibrotic or calcified scar”
Tx:	Surgical if symptomatic, otherwise conservative observation (especially for elderly/high risk patients)