Which cyst type is associated with high amylase in cyst fluid?

• A. IPMN
• B. SPN
• C. MCN
• D. Pancreatic pseudocyst

Answer: (D)

High amylase in cyst fluid points to a pancreatic pseudocyst. Pseudocysts form after pancreatitis when pancreatic juice leaks into a fluid collection that lacks an epithelial lining, so the cyst fluid resembles pancreatic secretions and is rich in enzymes like amylase. This enzyme-rich fluid is the hallmark that helps distinguish pseudocysts from other pancreatic cysts.

For other cyst types, the signal is different. Mucinous cystic neoplasms and intraductal papillary mucinous neoplasms usually show mucin production and elevated carcinoembryonic antigen (CEA) in the fluid, with amylase not being the defining feature. Solid pseudopapillary neoplasms tend to have cystic degeneration but the fluid is not characteristically high in amylase. So the consistently high amylase level most strongly indicates a pancreatic pseudocyst.