Thyroglobulin, Fine Needle Aspirate
Test Code
Clinical Significance
Thyroglobulin, Fine Needle Aspirate - 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.
Test Resources
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Test Details
Methodology
Reference Range(s)
| Negative | ≤1.0 ng/mL |
| Indeterminate | 1.1-10.0 ng/mL |
| Consistent with thyroid tissue or metastatic thyroid cancer | >10.0 ng/mL |
Alternative Name(s)
Preferred Specimen(s)
1 mL fine needle aspirate (FNA) or thyroid-tissue washings submitted in a sterile transport tube
Alternative Specimen(s)
Non-lymph node • Non-nodal soft tissue • Cervical node washings
Minimum Volume
0.8 mL
Collection Instructions
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 Container
Sterile transport tube
Transport Temperature
Frozen
Specimen Stability
- Room temperature: 14 days
- Refrigerated: 7 days
- Frozen: 28 days
Reject Criteria
Glass tubes
Setup Schedule
Freeze immediately and transport frozen sample to laboratory directly. Do not send specimens in glass tubes.
Refrigerated: 7 days
Frozen: 28 days