Thyroglobulin, Fine Needle Aspirate

Test Code

CPT Codes

Preferred Specimen
1 mL fine needle aspirate (FNA) or thyroid-tissue washings submitted in a sterile transport tube

Minimum Volume
0.8 mL

Other Acceptable Specimens
Non-lymph node • Non-nodal soft tissue • Cervical node washings

A 25-gauge needle is inserted obliquely within the transducer plane of view and moved back and forth (passes) through the nodule to compensate for patient movement and needle deflection. There is no suction device; cells move into the needle via capillary action. After collection of the cytology samples, withdraw between 0.10 and 0.25 mL of saline up through each needle and empty this fluid back through the needle into a tube. This is the needle washing used for analysis. Repeat the passes and saline washings from the same biopsied site and empty contents into the same tube. The washes from all needles are pooled (final volume 1 mL). Inspect specimen for visible blood or tissue contamination. If bloody, centrifuge specimen and transfer supernatant to a new tube to send to the laboratory. The supernatant, not the cellular materials, is used for analysis. If the specimen is clear, centrifugation is not necessary.
Freeze immediately and transport frozen sample to laboratory directly. Do not send specimens in glass tubes.

Transport Temperature

Specimen Stability
Room temperature: 14 days
Refrigerated: 7 days
Frozen: 28 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Glass tubes

Beckman Coulter Chemiluminescent

Setup Schedule
Set up: Tues, Thurs, Sat; Report available: 4-7 days

Reference Range
Negative≤1.0 ng/mL
Indeterminate1.1-10.0 ng/mL
Consistent with thyroid tissue or metastatic thyroid cancer>10.0 ng/mL

Clinical Significance
Clinically enlarged cervical lymph nodes with a history of thyroid cancer are usually assessed by fine-needle aspiration biopsy (FNAB) followed by a cytology. Thyroglobulin (Tg) is frequently elevated in malignant FNAB needle wash specimens and it's use may possibly augment or replace cytology.

Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.