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Test Code 199PT Carbohydrate Antigen 19-9 (CA 19-9), Peritoneal Fluid

Reporting Name

CA 19-9, Peritoneal Fluid

Useful For

An adjunct to cytology to differentiate between malignancy-related ascites and benign causes of ascites formation

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Peritoneal


Specimen 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

Specimen Stability Information

Specimen Type Temperature Time Special Container
Peritoneal Frozen (preferred) 90 days
  Ambient  7 days
  Refrigerated  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
199PT CA 19-9, Peritoneal Fluid 50781-4

 

Result ID Test Result Name Result LOINC Value
199PN CA 19-9, Peritoneal Fluid 50781-4
SITEE Site 39111-0

Interpretation

A peritoneal fluid carbohydrate antigen 19-9 (CA 19-9) concentration greater than 32 U/mL is suspicious, but not diagnostic, of a malignancy-related ascites. This clinical decision limit cutoff yielded 44% sensitivity and 93% specificity in a study of 137 patients presenting with ascites. However, ascites caused by malignancies not associated with increase serum CA 19-9 concentrations, including lymphoma, mesothelioma, leukemia, and melanoma, routinely had CA 19-9 concentrations less than 32 U/mL. Therefore, negative results should be interpreted with caution, especially in patients who have or are suspected of having a malignancy not associated with elevated CA 19-9 levels in serum.

Clinical Reference

1. Trape J, Molina R, Sant F: Clinical evaluation of the simultaneous determination of tumor markers in fluid and serum and their ratio in the differential diagnosis of serous effusions. Tumour Biol. 2004 Sep-Dec;25(5-6):276-281

2. Sari R, Yildirim B, Sevinc A, Bahceci F, Hilmioglu F: The importance of serum and ascites fluid alpha-fetoprotein, carcinoembryonic antigen, CA 19-9, and CA 15-3 levels in differential diagnosis of ascites etiology. Hepatogastroenterology. 2001 Nov-Dec;48(42):1616-1621

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. Jain T, Ram S, Kumar H, Saroch A, Sharma V, Singh H: Ascitic and serum levels of tumor biomarkers (CA 72-4, CA 19-9, CEA AND CA 125) in discrimination of cause of ascites: A prospective study. Arq Gastroenterol. 2022 Apr-Jun;59(2):198-203. doi: 10.1590/S0004-2803.202202000-37

Report Available

1 to 3 days

Method Name

Immunoenzymatic Assay