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HelpTest Code 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
Performing Laboratory
Mayo Clinic Laboratories in Rochester
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
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 |
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.
Report Available
1 to 3 daysReject Due To
| Gross hemolysis | Reject |
| Gross icterus | OK |
Method Name
Immunoenzymatic Assay
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.