From the Guidelines
The most important investigation for mucinous cystadenoma of the pancreas after fine needle aspiration (FNA) of the cyst fluid is carcinoembryonic antigen (CEA) level measurement in the aspirated fluid. This is based on the most recent and highest quality study available, which suggests that a CEA level greater than 192 ng/mL is 80% accurate for the diagnosis of a mucinous cyst 1. The following points highlight the importance of CEA level measurement:
- CEA is a glycoprotein tumor marker that is typically elevated in mucinous pancreatic cysts.
- A CEA level greater than 192 ng/mL strongly suggests a mucinous lesion.
- This test helps differentiate mucinous from non-mucinous cysts, which is crucial for management decisions since mucinous cysts have malignant potential.
- Additional analyses of the cyst fluid should include cytology to look for malignant cells, amylase levels to rule out pseudocysts, and viscosity assessment.
- The combination of these tests, particularly CEA levels, provides the most valuable diagnostic information after FNA to guide treatment decisions, which may range from surveillance for benign-appearing mucinous cystadenomas to surgical resection for those with concerning features or high malignant potential. Other studies also support the use of CEA level measurement, with a sensitivity of 52–78% and specificity of 63–91% for distinguishing mucinous from non-mucinous cysts 1. However, it is essential to note that CEA levels are not predictive of malignancy in mucin-producing cysts, and other markers such as KRAS mutations and microsatellite loss of heterozygosity may be useful in diagnostic stratification 1. In summary, CEA level measurement is the most important investigation for mucinous cystadenoma of the pancreas after FNA of the cyst fluid, and it should be used in conjunction with other tests to guide treatment decisions.
From the Research
Characteristic Investigation of Mucinous Cystadenoma
The most important investigation for mucinous cystadenoma of the pancreas after Fine Needle Aspiration (FNA) of the cyst fluid is:
- High CEA in cyst fluid, as it is a reliable marker for distinguishing mucinous from non-mucinous cysts 2, 3, 4, 5, 6
Key Findings
- CEA levels are significantly higher in mucinous cystadenomas compared to pseudocysts and serous cystadenomas 2, 3, 5
- A CEA level of > 192 ng/mL is considered a useful test for identifying mucinous cysts, including mucinous cystadenomas and intraductal papillary mucinous neoplasms (IPMNs) 4
- The combination of viscosity, CEA, and cytology can reliably distinguish malignant cystic tumors and potentially premalignant mucinous cystic neoplasms from pseudocysts and serous cystadenomas 2
- Elevated CEA (> or =480 ng/mL) and viscosity (>1.6) accurately predict mucinous cystic neoplasms (MCNs) from serous cystadenomas and pseudocysts 3
Diagnostic Markers
- CEA is a more reliable marker than amylase, CA 125, and CA 19-9 for distinguishing mucinous from non-mucinous cysts 2, 3, 5
- Amylase levels are higher in pseudocysts compared to mucinous cystadenomas and serous cystadenomas 2, 3, 5
- Viscosity is also a useful marker, with high values (>1.6) indicating mucinous tumors 3