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HelpTest ID: PF199 Carbohydrate Antigen 19-9 (CA 19-9), Pleural Fluid
Reporting Name
CA 19-9, Pleural FluidUseful For
An adjuvant to cytology and imaging studies to differentiate between nonmalignant and malignant causes of pleural effusions
Specimen Type
Pleural FluidSpecimen Required
Patient Preparation: For 12 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.
Container/Tube: Plain, plastic, screw-top tube
Specimen Volume: 2 mL
Specimen Minimum Volume
0.5 mL (Samples <0.5 mL may be rejected)
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Pleural Fluid | Frozen (preferred) | 90 days | |
| Refrigerated | 14 days | ||
| Ambient | 7 days |
Reference Values
An interpretive report will be provided.
Day(s) Performed
Monday through Saturday
Test Classification
This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
86301
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PF199 | CA 19-9, Pleural Fluid | 19163-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| P199 | CA 19-9, Pleural Fluid | 19163-5 |
| SITE8 | Site | 39111-0 |
Clinical Information
Pleural effusions occur as a consequence of either nonmalignant conditions (including congestive heart failure, pneumonia, pulmonary embolism, and liver cirrhosis) or malignant conditions (including lung, breast, and lymphoma cancers). Diagnosing the cause of an effusion can be difficult, requiring cytological examination of the fluid. Analysis of various tumor markers in pleural fluid has shown that these markers can differentiate between effusions caused by nonmalignant and malignant conditions and can enhance cytology findings.
Carbohydrate antigen 19-9 (CA 19-9) is a modified Lewis(a) blood group antigen. Healthy adults typically produce low to undetectable levels of CA 19-9. Serum concentrations of CA 19-9 may be elevated in patients with certain malignancies that secrete CA 19-9 into circulation, including cholangiocarcinoma, colorectal, stomach, bile duct, lung, ovarian, and pancreatic cancers.
Pleural fluid concentrations of CA 19-9 have been reported to be elevated in patients with certain malignancies. Malignancies that can secrete CA 19-9 and elevate serum CA 19-9 concentrations, including cholangiocarcinoma, colorectal, stomach, bile duct, lung, ovarian, and pancreatic cancers, typically also elevate CA 19-9 in pleural fluid. In contrast, malignancies that do not secrete CA 19-9, including mesothelioma, lymphoma, leukemia, and melanoma, have low concentrations of CA 19-9 in pleural fluid comparable to concentrations observed in nonmalignant effusions.
CA 19-9 results should be used in conjunction with cytological analysis of pleural fluid, imaging studies, and other clinical findings.
Interpretation
A pleural fluid carbohydrate antigen 19-9 (CA 19-9) concentration of 20.0 U/mL or higher is suspicious, but not diagnostic, of a malignant source of the effusion. This cutoff yielded a sensitivity of 35%, specificity of 95%, and positive predictive value of 88% in a study of 200 patients presenting with effusion. CA 19-9 concentrations were significantly higher in effusions caused by CA 19-9-secreting malignancies, including cholangiocarcinoma, colorectal, stomach, bile duct, lung, ovarian, and pancreatic cancers. However, effusions caused by non-CA 19-9-secreting malignancies, including lymphoma, mesothelioma, leukemia, and melanoma, routinely had CA 19-9 concentrations below 20.0 U/mL. Therefore, negative results should be interpreted with caution, especially in patients who have or are suspected of having a non-CA 19-9-secreting malignancy.
Correlation of all tumor marker results with cytology and imaging is highly recommended.
Clinical Reference
1. Shitrit D, Zingerman B, Shitrit ABG, Shlomi D, Kramer MR: Diagnostic value of CYFRA 21-1, CEA, CA 19-9, CA 15-3, and CA 125 assays in pleural effusions: analysis of 116 cases and review of the literature. Oncologist. 2005 Aug;10(7):501-507
2. Hackbarth JS, Murata K, Reilly WM, Algeciras-Schimnich A: Performance of CEA and CA19-9 in identifying pleural effusions caused by specific malignancies. Clin Biochem. 2010 Sep;43(13-14):1051-1055
3. Block DR, Algeciras-Schimnich A: Body fluid analysis: clinical utility and applicability of published studies to guide interpretation of today's laboratory testing in serous fluids. Crit Rev Clin Lab Sci. 2013 Jul-Oct;50(4-5):107-124. doi: 10.3109/10408363.2013.844679
4. Yang Y, Liu YL, Shi HZ: Diagnostic accuracy of combinations of tumor markers for malignant pleural effusion: An updated meta-analysis. Respiration. 2017;94(1):62-69. doi: 10.1159/000468545
Report Available
1 to 3 daysMethod Name
Immunoenzymatic Assay
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.
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