Laboratory Medicine

Test catalogue

Thyroglobulin, Fluids (Fine-Needle Aspiration Biopsy Needle Wash).
Test Name Thyroglobulin, Fluids (Fine-Needle Aspiration Biopsy Needle Wash). Clinical information Thyroglobulin (Tg) is a glycoprotein exclusively produced by the follicular cells of the thyroid; therefore, detection of Tg in athyrotic individuals facilitates detection of persistence, recurrence, or metastasis of thyroid carcinoma. Most metastases of papillary thyroid cancer occur in the lymph nodes in the neck. Suspicious nodes undergo fine needle aspiration (FNA) cytological examination to determine diagnosis. However, 1 out of every 5 samples has inadequate cellularity, necessitating Tg testing in FNA-needle wash.
Specimen Type / Requirements Container Type = Sterile Container Minimum Testing Volume = 1mL Body Fluid Preferred needle wash volume: 1.0 mL (Minimum 0.5 mL)
Specimen Handling Collection Instructions: See below for step-by-step instructions: Prepare normal saline for needle wash and keep it accessible (Saline is the only acceptable solution for needle washings) Following FNA biopsy (FNAB), expel collected material onto a slide for cytological analysis After each fine-needle aspiration biopsy (FNAB) has been collected and the material in the needle has been expelled onto a slide for cytologic analysis, attach the used FNAB needle to an empty syringe. Withdraw between 0.10 mL and 0.25 mL of saline up through the needle until the saline starts to fill the hub of the needle or end of the syringe. Expel this fluid back through the needle into a separate plastic aliquot tube/container. This is the needle washing used for analysis. Repeat steps 2 through 4 for each needle pass of the same biopsied site and empty into the same tube, accumulating a total of 0.5 mL to 1.0 mL of fluid to send to the laboratory. (If more than 1 site is biopsied, see Additional Information) Lab to Inspect specimen for visible blood or tissue contamination: (a). If bloody, lab to centrifuge specimen and transfer supernatant to a new plastic aliquot tube (5-mL standard tube). The supernatant, not the cellular material, is used for analysis. (b) If specimen is clear, centrifugation is not necessary. 8. Lab to freeze within 2 to 4 hours of collection (if not analyzed immediately). Additional Information (multiple biopsy sites) If more than 1 site is biopsied, each washing material should be submitted on a separate tube and under a different order number. A minimum of 0.5 mL is required for testing; however, the total collection volume should not exceed 1.5 mL. Specimen volumes outside these parameters may be rejected. Do not send a saline control. This test has been validated to rule-out saline matrix effect. Specimen Handling Freeze within 4 hours of collection. Centrifuge to remove cellular material. Stability: Stable at room temperature or refrigerated for 8 hours, and frozen for 90 days. Transportation: Send sample to core lab as soon as possible.
Documentation For Non-Electronic Orders
Turnaround Time (TAT) 5 days	Test Utilization
Reference Value Thyroglobulin Fine-Needle Aspiration Biopsy Needle Wash <= 7.4 ug/L The lab has not established reference intervals for thyroglobulin on other fluid types.
Test Code LAB7544	Methodology Roche Immunoassay
Testing Location SMH-Biochemistry	Other Information Last Updated: Jan 20, 2026

Thyroglobulin, Fluids (Fine-Needle Aspiration Biopsy Needle Wash).

Test Name

Thyroglobulin, Fluids (Fine-Needle Aspiration Biopsy Needle Wash).

Clinical information

Thyroglobulin (Tg) is a glycoprotein exclusively produced by the follicular cells of the thyroid; therefore, detection of Tg in athyrotic individuals facilitates detection of persistence, recurrence, or metastasis of thyroid carcinoma.

Most metastases of papillary thyroid cancer occur in the lymph nodes in the neck. Suspicious nodes undergo fine needle aspiration (FNA) cytological examination to determine diagnosis. However, 1 out of every 5 samples has inadequate cellularity, necessitating Tg testing in FNA-needle wash.

Specimen Type / Requirements

Container Type = Sterile Container

Minimum Testing Volume = 1mL Body Fluid

Preferred needle wash volume: 1.0 mL (Minimum 0.5 mL)

Specimen Handling

Collection Instructions: See below for step-by-step instructions:

Prepare normal saline for needle wash and keep it accessible (Saline is the only acceptable solution for needle washings)
Following FNA biopsy (FNAB), expel collected material onto a slide for cytological analysis
After each fine-needle aspiration biopsy (FNAB) has been collected and the material in the needle has been expelled onto a slide for cytologic analysis, attach the used FNAB needle to an empty syringe.
Withdraw between 0.10 mL and 0.25 mL of saline up through the needle until the saline starts to fill the hub of the needle or end of the syringe.
Expel this fluid back through the needle into a separate plastic aliquot tube/container. This is the needle washing used for analysis.
Repeat steps 2 through 4 for each needle pass of the same biopsied site and empty into the same tube, accumulating a total of 0.5 mL to 1.0 mL of fluid to send to the laboratory. (If more than 1 site is biopsied, see Additional Information)
Lab to Inspect specimen for visible blood or tissue contamination:

8. Lab to freeze within 2 to 4 hours of collection (if not analyzed immediately).

Additional Information (multiple biopsy sites)

If more than 1 site is biopsied, each washing material should be submitted on a separate tube and under a different order number.
A minimum of 0.5 mL is required for testing; however, the total collection volume should not exceed 1.5 mL. Specimen volumes outside these parameters may be rejected.
Do not send a saline control. This test has been validated to rule-out saline matrix effect.

Specimen Handling Freeze within 4 hours of collection. Centrifuge to remove cellular material.

Stability: Stable at room temperature or refrigerated for 8 hours, and frozen for 90 days.

Transportation: Send sample to core lab as soon as possible.

Documentation For Non-Electronic Orders

Turnaround Time (TAT)

5 days

Test Utilization

Reference Value

Thyroglobulin Fine-Needle Aspiration Biopsy Needle Wash <= 7.4 ug/L The lab has not established reference intervals for thyroglobulin on other fluid types.

Test Code

LAB7544

Methodology

Roche Immunoassay

Testing Location

SMH-Biochemistry

Other Information

Last Updated: Jan 20, 2026