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Test ID: BHSF Beta-Human Chorionic Gonadotropin, Quantitative, Spinal Fluid

Reporting Name

Chorionic Gonad Beta-Subunit QN,CSF

Useful For

Aiding in the diagnosis of brain metastases of testicular cancer or extragonadal intracerebral germ cell tumors

Clinical Information

Human chorionic gonadotropin (hCG) is synthesized during pregnancy by syncytiotrophoblast cells. hCG may also be produced by neoplastic cells of testicular tumors (seminomas or nonseminomas), ovarian germ cell tumors, gestational trophoblastic disease, choriocarcinoma and various nontrophoblastic tumors including breast, ovarian, pancreatic, cervical, gastric, and hepatic cancers.

 

Measurement of hCG is used as an adjunct in the diagnosis of germ cell tumors. The presence of hCG in cerebrospinal fluid (CSF) is suggestive of tumor presence. Pure germinomas are associated with low hCG concentrations in both serum and CSF. A subset of nongerminomatous germ cell tumors contains syncytiotrophoblastic giant cells. These tumors are associated with moderately increased hCG concentrations (<1,000 IU/L) in the serum and/or CSF, and the survival rate in patients suffering these tumors is worse than that of patients with pure germinomas. In contrast, choriocarcinomas, another subset of nongerminomatous germ cell tumors, are associated with very high hCG concentrations (>1,000 IU/L) in both serum and CSF. Quantification of the hCG in CSF can be important in guiding treatment and monitoring response to treatment of these tumors.

 

The combination of the specific antibodies used in the Roche Beta HCG immunoassay recognize the holo-hormone, "nicked" forms of hCG, the beta-core fragment, and the free beta-subunit.

Interpretation

Elevated levels of human chorionic gonadotropin in spinal fluid indicate the probable presence of central nervous system metastases or recurrence of tumor in patients with germ cell tumors, including patients with testicular cancer or choriocarcinoma.

Analytic Time

1 day

Day(s) and Time(s) Performed

Monday through Friday; 6 a.m.-12 a.m.

Saturday; 6:30 a.m.-5 p.m.

Clinical Reference

1. Tian C, Shi Q, Xiao G, et al: CSF and serum hCG in patients without gestational and neoplastic hCG-secretion. Scand J Clin Lab Invest.2011;71:264-268

2. Tian C, Shi Q, Pu C, et al: Re-evaluation of the significance of cerebrospinal fluid human chorionic gonadotropin in detecting intracranial ectopic germinoas. J Clin Neurosci. 2011;18:223-226

3. Gonzalez-Sanchez V, Moreno-Perez O, Pellicer PS, et al: Validation of the human chorionic gonadotropin immunoassay in cerebrospinal fluid for the diagnostic work-up of neurohypophyseal germinomas. Ann Clin Biochem. 2011;48:433-437

Method Name

Electrochemiluminescent Immunoassay

Specimen Type

CSF


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: Sterile vial

Specimen Volume: 1 mL


Specimen Minimum Volume

0.75 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
CSF Refrigerated (preferred) 28 days
  Ambient  14 days
  Frozen  14 days

Reference Values

<1.0 IU/L

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

84702

LOINC Code Information

Test ID Test Order Name Order LOINC Value
BHSF Chorionic Gonad Beta-Subunit QN,CSF 14041-8

 

Result ID Test Result Name Result LOINC Value
BHSF Chorionic Gonad Beta-Subunit QN,CSF 14041-8
Mayo Clinic Laboratories | Endocrinology Catalog Additional Information:

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