Carcinoembryonic Antigen (CEA), Pancreatic Cyst Fluid
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Cystic lesions of the pancreas are of various types including:
- Inflammatory cysts (pseudocysts)
- Serous cysts (serous cystadenoma)
- Premalignant (mucinous cystadenoma)
- Malignant (cystadenocarcinoma, intrapapillary mucinous neoplasia)
The diagnosis of pancreatic cyst type is often difficult and may require correlating imaging studies with results of cytologic examination and tumor marker testing performed on cyst aspirates. Various tumor markers have been evaluated to distinguish nonmucinous, nonmalignant pancreatic cysts from mucinous cysts, which have a high likelihood of malignancy. Carcinoembryonic antigen (CEA) has been found to be the most reliable tumor marker for identifying those pancreatic cysts that are likely mucinous. In cyst aspirates, CEA concentrations > or =200 ng/mL are highly suspicious for mucinous cysts. The greater the CEA concentration, the greater the likelihood that the mucinous cyst is malignant. However, CEA testing does not reliably distinguish between benign, premalignant, or malignant mucinous cysts. CEA test results should be correlated with the results of imaging studies, cytology, other cyst fluid tumor markers (ie, amylase and CA 19-9), and clinical findings for diagnosis.
When used in conjunction with imaging studies, cytology, and other pancreatic cyst fluid tumor markers:
-Distinguishing between mucinous and nonmucinous pancreatic cysts
-Determining the likely type of malignant pancreatic cyst
A pancreatic cyst fluid carcinoembryonic antigen (CEA) concentration of > or =200 ng/mL is very suggestive for a mucinous cyst but is not diagnostic. The sensitivity and specificity for mucinous lesions are approximately 62% and 93%, respectively, at this concentration. Cyst fluid CEA concentrations of < or =5 ng/mL indicate a low risk for a mucinous cyst, and are more consistent with serous cystadenoma, fluid collections complicating pancreatitis, cystic neuroendocrine tumor, or metastatic lesions. CEA values between these extremes have limited diagnostic value.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
These test results should not be the sole basis for diagnosis. Test results should be always correlated with imaging and cytology.
This test does not distinguish between malignant and nonmalignant mucinous cysts.
This test should not be ordered for pancreatic fluid of noncyst origin (eg, pancreatic duct fluid; peripancreatic fluid) since reference values have not been established for this specimen type. Contact Mayo Medical Laboratories for ordering assistance.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Brugge WR, Lewandrowski K, Lee-Lewandrowski E, et al: Diagnosis of pancreatic cystic neoplasms: a report of cooperative pancreatic cyst study. Gastroenterology 2004, May;126:1330-1336
2. Snozek CL, Jenkins SM, Bryant SC, et al: Analysis of CEA, CA 19-9, and amylase in pancreatic cyst fluid for diagnosis of pancreatic lesions. Clin Chem 2008;54 (Suppl S):A126-127
3. Khalid A, Brugge W: ACG practice guidelines for the diagnosis and management of neoplastic pancreatic cysts. Am J Gastroenterol 2007 Oct;102(10):2339-2349