For 12 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements
1. Needle wash specimens for analysis should be collected in conjunction with cytology specimens.
2. Have saline available prior to start of procedure. Saline is the only acceptable solution for needle washings.
3. 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.
4. 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.
5. Expel this fluid back through the needle into a separate plastic aliquot tube. This is the needle washing used for analysis.
6. 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 1.5 mL of fluid to send to the laboratory.
Inspect specimen for visible blood or tissue contamination:
a. If bloody, centrifuge specimen and transfer supernatant to a new plastic aliquot tube (5-mL standard tube) to send to laboratory. The supernatant, not the cellular material, is used for analysis.
b. If specimen is clear, centrifugation is not necessary.
Refrigerate within 1 to 2 hours of collection and freeze within 2 to 4 hours of collection.
Plain, plastic, screw-top tube
Frozen (preferred) - 90 days
Refrigerated - 14 days
Ambient - 7 days
Lymph node: ≤ 1.0 ng/mL
This cutoff has been validated for total needle wash volumes of ≤1.5 mL of normal saline. If wash volumes are substantially larger, a lower cutoff might apply.
Non Lymph node: an interpretation will be provided