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Test ID 199PC Carbohydrate Antigen 19-9 (CA 19-9), Pancreatic Cyst Fluid


Ordering Guidance


This test should not be ordered for pancreatic fluid of noncystic origin (eg, pancreatic duct fluid, peripancreatic fluid) since reference values have not been established for those specimen types. For ordering assistance call 800-533-1710.



Specimen Required


Patient Preparation: For 12 hours before this procedure 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: 1 mL


Useful For

As an adjunct in the assessment of pancreatic cysts, when used in conjunction with carcinoembryonic antigen, amylase, imaging studies and cytology

Method Name

Immunoenzymatic Assay

Reporting Name

CA19-9, Pancreatic Cyst

Specimen Type

Pancreatic Cyst Fluid

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Pancreatic Cyst Fluid Frozen (preferred) 90 days
  Refrigerated  7 days
  Ambient  72 hours

Clinical Information

Carbohydrate antigen 19-9 (CA 19-9) is a modified Lewis(a) blood group antigen that has been used as a tumor marker. Serum CA 19-9 concentrations may be elevated in patients with gastrointestinal malignancies, such as cholangiocarcinoma, colon cancer, or pancreatic cancer. While serum CA 19-9 is neither sensitive nor specific for pancreatic cancer, concentrations of CA 19-9 in pancreatic cyst fluid may help determine whether a pancreatic cyst is benign.

 

Cystic lesions of the pancreas are of various types:

Benign cysts:

-Inflammatory cysts (pseudocysts)

-Serous cysts (serous cystadenoma)

 

Mucinous cysts:

-Premalignant (mucinous cystadenoma)

-Malignant (cystadenocarcinoma, intrapapillary mucinous neoplasia)

 

Pancreatic cyst fluid CA 19-9 results should be used in conjunction with imaging studies, cytology, and other cyst-fluid tumor markers, such as carcinoembryonic antigen and amylase.

Reference Values

An interpretive report will be provided.

Cautions

Carbohydrate antigen 19-9 (CA 19-9) and other tumor markers are not specific for malignancy, and CA 19-9 testing has limited utility when used as the sole tumor marker test. Other tests (eg, carcinoembryonic antigen, amylase, cytology) should be performed in conjunction with CA 19-9 for assessing pancreatic cyst aspirates.

 

A low or negative result (<5 U/mL) may be uninformative or misleading since some individuals (Lewis nonsecretors) do not produce the CA 19-9 antigen. In such cases, a serum CA 19-9 measurement is necessary to verify that the patient is (or is not) a CA 19-9 secretor.

 

In rare cases, some individuals can develop antibodies to mouse or other animal antibodies (often referred to as human anti-mouse antibodies [HAMA] or heterophile antibodies), which may cause interference in some immunoassays. Caution should be used in interpretation of results, and the laboratory should be alerted if the result does not correlate with the clinical presentation.

Day(s) Performed

Monday through Friday

Report Available

1 to 3 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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

NY State Approved

Yes