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Test ID CORT Cortisol, Serum

Useful For

Discrimination between primary and secondary adrenal insufficiency

 

Differential diagnosis of Cushing syndrome

 

This test is not recommended for evaluating response to metyrapone.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Ordering Guidance


The preferred screening test for Cushing syndrome measures 24-hour urinary free cortisol. Order CORTU / Cortisol, Free, 24 Hour, Urine.

 

For confirming the presence of synthetic steroids, order SGSS / Synthetic Glucocorticoid Screen, Serum.

 

For patients taking exogenous glucocorticoids, order CORTU / Cortisol, Free, 24 Hour, Urine.

 

For evaluating response to metyrapone, order DCORT / 11-Deoxycortisol, Serum.

 

For evaluation of congenital adrenal hyperplasia, the following tests provide better, accurate, and specific determination of the enzyme deficiency:

-DCORT / 11-Deoxycortisol, Serum

-OHPG / 17-Hydroxyprogesterone, Serum

-DHEA_ / Dehydroepiandrosterone (DHEA), Serum



Specimen Required


Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.6 mL serum

Collection Instructions:

1. Morning (8 a.m.) and afternoon (4 p.m.) specimens are preferred.

2.Within 2 hours of collection, centrifuge the specimen.

3. For red-top tubes aliquot the serum into a plastic vial after centrifugation.

Additional Information:

1. Include time of collection.

2. If multiple specimens are collected, send separate order for each specimen.


Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 14 days
  Frozen  90 days
  Ambient  7 days

Reference Values

0-<3 months: 1.1-19 mcg/dL

3 months-<12 months: 2.6-23 mcg/dL

12 months-<13 years: 2.2-13 mcg/dL

13 years-<16 years: 3.0-17 mcg/dL

16 years-<18 years: 3.8-19 mcg/dL

≥18 years:

a.m.: 7-25 mcg/dL

p.m.: 2-14 mcg/dL

 

For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html

Day(s) Performed

Monday through Saturday

CPT Code Information

82533

Report Available

1 to 3 days

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Gross icterus OK

Secondary ID

8545