Prolactin, Pituitary Macroadenoma, Serum
Use
This test is useful for quantifying prolactin in serum specimens where the high-dose hook effect is suspected, such as in the presence of a pituitary tumor with symptoms of prolactinoma and lower than expected serum prolactin concentration. The measurement of prolactin can aid in the diagnosis and management of conditions like prolactin-secreting pituitary adenoma, which is known to cause hyperprolactinemia. Accurate measurement is crucial as high serum prolactin concentrations can result in falsely low readings due to the high-dose hook effect in certain immunometric assays.
Special Instructions
Prior to ordering this test, a pituitary adenoma should be identified by imaging studies. Patient's age and sex are required for test processing. If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen. For initial patient assessment, PRL / Prolactin, Serum should be ordered as the screening test.
Limitations
This test may not detect nonfunctional macroadenomas which do not secrete prolactin. There might be interference due to antibodies like human antianimal antibodies in individuals exposed to animals or those treated with immunoglobulin therapies. Interference can also occur due to extreme titers of antibodies against analyte-specific antibodies, streptavidin, or ruthenium. Apparent hyperprolactinemia caused by macroprolactin presence may not be detected without additional testing (order MCRPL / Macroprolactin, Serum if needed).
Methodology
Immunoassay (ECLIA)
Biomarkers
LOINC Codes
- 20568-2
- 20568-2
- 48767-8
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
2 mL
Minimum Volume
1.75 mL
Container
Plastic vial
Collection Instructions
Centrifuge and aliquot serum into a plastic vial.
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 24 hours |
| Refrigerated | 7 days |
| Frozen | 90 days |
