Laboratory Services

Thyroid Cascade

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Updated Test Information:

Test Description
Thyroid Cascade
Synonym(s)

Thyroid Function Cascade

Test ID
TSHC
General Information

Thyroid-stimulating hormone (TSH) with reflex to FT4, T3, and/or thyroid peroxidase (anti-TPO) antibodies depending on the results. If reflex testing is performed, additional charges/CPT code(s) may apply. If TSH is <0.27 mIU/L, then free T4 (FT4) is performed. If FT4 is normal and the TSH is <0.1 mIU/L, then T3 is performed. If TSH is >4.2 mIU/L, then FT4 and thyroperoxidase antibodies are performed.

Specimen Type

Serum

Specimen Requirements

SST

Stability

8 days at 20-25 °C
8 days at 2-8 °C
12 months at -20 °C (± 5 °C)

Department (code)

Chemistry

Methodology

Electrochemiluminescence immunoassay (ECLIA)

Estimated TAT

0-2 days

Testing Schedule

Monday-Saturday

CPT Code(s)

84443. If reflexed, additional charges will apply

Minimum Sample Volume

0.5

Performing Lab

Incyte Diagnostics