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HelpTest Code THSCM Thyroid Function Cascade, Serum
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Reporting Name
Thyroid Function Cascade, SSpecimen Type
SerumSpecimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL
Collection Instructions:
1. Serum gel tubes should be centrifuged within 2 hours of collection.
2. Red-top tubes should be centrifuged and the serum aliquoted into a plastic vial within 2 hours of collection.
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | OK |
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 7 days | |
| Frozen | 30 days | ||
| Ambient | 72 hours |
Specimen Minimum Volume
1 mL
Special Instructions
Day(s) Performed
Monday through Sunday
Specimen Retention Time
7 daysReport Available
1 to 2 daysReference Values
0-5 days: 0.7-15.2 mIU/L
6 days-2 months: 0.7-11.0 mIU/L
3-11 months: 0.7-8.4 mIU/L
1-5 years: 0.7-6.0 mIU/L
6-10 years: 0.6-4.8 mIU/L
11-19 years: 0.5-4.3 mIU/L
≥20 years: 0.3-4.2 mIU/L
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| FRT4C | T4 (Thyroxine), Free, S | Yes, (order FRT4) | No |
| TPOC | Thyroperoxidase Ab, S | Yes, (order TPO) | No |
| T3C | T3 (Triiodothyronine), Total, S | Yes, (order T3) | No |
Useful For
Screening for a diagnosis of thyroid disease
Testing Algorithm
If thyrotropin (TSH, formerly thyroid-stimulating hormone) is less than 0.3 mIU/L, then free T4 (thyroxine) is performed at an additional charge.
If FT4 is normal and the TSH is less than 0.1 mIU/L, then T3 (triiodothyronine) is performed at an additional charge.
If TSH is greater than 4.2 mIU/L, then free T4 and thyroperoxidase antibodies are performed at an additional charge.
For more information see Thyroid Function Ordering Algorithm.
CPT Code Information
84443
84439 (if appropriate)
84480 (if appropriate)
86376 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| THSCM | Thyroid Function Cascade, S | 11579-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| STSHC | TSH, Sensitive, S | 11579-0 |
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| STSHC | TSH, Sensitive, S | Yes, (order STSH) | Yes |