Laboratory Test Information Guide

Details for Thyroglobulin, Fine Needle Aspirate

Test Name: Thyroglobulin, Fine Needle Aspirate
Alternate Name(s):  
Laboratory: Core
Specimen Type: Two samples:
The first is uncontaminated Plasma-Lyte and serves as a blank.
The second is 1 mL (or more) of Plasma-Lyte that has been used to rinse the 10 mL syringe used for the biopsy.
Collection Information: A physician will perform the biopsy. Using a 22-27-gauge needle attached to a 10 mL syringe, several drops of the aspirated material are placed and smeared onto glass slides for cytological examination. This specimen goes to the Pathology Laboratory.

Two 50 mL conical tubes are prepared, each containing 1 mL of Plasma-Lyte solution. The sample syringe from the biopsy is then flushed into one of the 1 mL Plasma-Lyte solutions (tube labelled “THYRFNR-FNA in Plasmalyt sol”). The other tube is labelled “THYRBW – Plasmalyt sol”. Both aliquots are transported to the Core Laboratory.
Test Schedule: Thursday
0800 - 1600
Turnaround time from when specimen
is received in testing laboratory:
5 days
Reference Range: After blank subtraction, the reference interval is ≤ 0.1 µg/L (limit of quantitation for thyroglobulin assay)
Effective Date: 2017-07-04
Revised Date: 2018-03-06
Critical Value:  
Interpretive Comments: An elevated thyroglobulin level in the fine needle aspirate may indicate the presence of metastatic differentiated thyroid cancer.
Special Processing: Once the samples are received by the Core Laboratory, they will be aliquoted and centrifuged (1500 x g, 2 minutes), and the supernatants will be frozen if the thyroglobulin concentration will not be measured that day.

The thyroglobulin concentration obtained on the blank sample will be subtracted from the thyroglobulin concentration obtained on the needle rinse from the fine needle aspirate. If a blank result of > 0.1 µg/L is obtained, a technical investigation will be performed prior to reporting of result.
Method of Analysis: Roche Electrochemiluminescence
Critical Information Required:  
Storage & Shipment:  
System Codes: 
Referred To:  

Questions? Comments? Contact Laura Gopaul