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HelpTest Code PLPMA Prolactin, Pituitary Macroadenoma, Serum
Useful For
Quantifying prolactin in serum specimens where the high-dose hook effect is suspected (eg, presence of pituitary tumor with symptoms of prolactinoma, and lower than expected serum prolactin concentration)
Testing Algorithm
A pituitary adenoma should be identified by imaging studies prior to ordering this test.
Reporting Name
Prolactin, Pituitary MacroadenomaSpecimen Type
SerumOrdering Guidance
For initial patient assessment; order PRL / Prolactin, Serum as the screening test.
Necessary Information
Patient's age and sex are required.
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 2 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
1.75 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 7 days | |
| Frozen | 90 days | ||
| Ambient | 24 hours |
Reference Values
Males
<18 years: not established
≥18 years: 4.0-15.2 ng/mL
Females:
<18 years: not established
≥18 years: 4.8-23.3 ng/mL
Interpretation
If no high-dose hook effect is observed, the following report comment will be included with the prolactin result: 10-, 100-, and 400-fold dilutions produced results consistent with the absence of high-dose hook effect. Total prolactin was measured using the Roche Cobas e immunoassay analyzer.
If a high-dose hook effect is observed, which is demonstrated by significantly increasing concentrations of prolactin obtained after dilution of the serum, an interpretive comment will be included with the prolactin result.
The Roche Cobas Prolactin II assay should demonstrate no high-dose hook effect at prolactin concentrations up to approximately 12,500 ng/mL).
Clinical Reference
1. Winter WE, McCormack A, Bertholf RL: Chapter 65: Pituitary function and pathophysiology. In Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Sixth edition. Edited by N Rafai, AR Horvath, CT Wittwer. Elsevier, 2018, pp 1492-1529
2. Schoft C, Schofl-Siegert B, Hinrich Karstens J, et al: Falsely low serum prolactin in two cases of invasive macroprolactinoma. Pituitary 2002;5:261-265
3. Casaneuva FF, Molitch ME, Schlecte JA, et al: Guidelines of the Pituitary Society for the diagnosis and management of prolactinomas. Clin Endocrinol 2006;65:265-273
4. Melmed S, Casanueva FF, Hoffman AR, et al: Diagnosis and treatment of hyperprolactinemia: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2011 Feb;96(2):273-288
Day(s) Performed
Report Available
Same day/1 to 2 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
84146
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PLPMA | Prolactin, Pituitary Macroadenoma | 20568-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| PRLR | Prolactin, S | 20568-2 |
| CMT89 | Comment | 48767-8 |
Method Name
Electrochemiluminescent Immunoassay
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.
Diluted Prolactin
LabCorp 142035