Home
HelpTest ID CATLN Calcitonin, Fine-Needle Aspiration Biopsy (FNAB)-Needle Wash, Lymph Node
Useful For
As an adjunct to cytologic examination of fine-needle aspiration specimens in athyrotic individuals treated for medullary thyroid carcinoma to confirm or exclude metastases in enlarged or ultrasonographically suspicious lymph nodes
Method Name
Immunoenzymatic Assay
Reporting Name
Calcitonin, FNAB, Lymph NodeSpecimen Type
Fine Needle WashContainer/Tube: Plain, plastic, screw-top tube
Specimen Volume: 1 to 1.5 mL
Collection Instructions: Needle wash specimens for analysis should be collected in conjunction with cytology specimens.
1. Have saline available prior to start of procedure. Saline is the only acceptable solution for needle washings.
2. 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.
3. 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.
4. Expel this fluid back through the needle into a separate tube. This is the needle washing used for analysis.
5. 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. (If more than 1 site is biopsied, see Note)
6. 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.
7. Refrigerate within 1 to 2 hours of collection and freeze within 2 to 4 hours of collection. Send frozen to the laboratory.
Note: If more than 1 site is biopsied, each washing material should be submitted on a separate tube and under a different order number. The biopsied site of each specimen must be clearly identified in LIS and/or batch sheet.
Additional Information: A minimum of 0.5 mL is required for testing; however, the total collection volume should not exceed 1.5 mL. Sample volumes outside these parameters may be rejected.
Forms: If not ordering electronically, complete, print, and send an Oncology Test Request Form (T729) with the specimen
(http://www.mayomedicallaboratories.com/it-mmfiles/oncology-request-form.pdf)
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Fine Needle Wash | Frozen (preferred) | 7 days |
| Refrigerated | 4 hours |
Clinical Information
Calcitonin is a polypeptide hormone secreted by the
parafollicular cells (also referred to as calcitonin cells or
C-cells) of the thyroid gland. Malignant tumors arising from
thyroid C-cells (medullary thyroid carcinoma: MTC) usually produce
elevated levels of calcitonin. MTC is an uncommon malignant thyroid
tumor, comprising <5% of all thyroid malignancies. Measurement
of serum calcitonin is used in the follow-up of patients who
underwent surgical removal of the thyroid gland.
Studies have reported that the measurement of calcitonin
in fine-needle aspiration biopsy (FNAB)-needle washes improves the
evaluation of suspicious lymph nodes in patients with a history of
MTC when used in combination with cytology. Comparing the results
of calcitonin in the needle rinse with serum calcitonin is highly
recommended. An elevated calcitonin in the serum could falsely
elevate calcitonin in the washings, if the rinse is contaminated
with blood. In these cases only calcitonin values significantly
higher than the serum should be considered as true-positives.
Cytologic examination and measurement of calcitonin can be
performed on the same specimen. To measure calcitonin, the FNA
needle is rinsed with a small volume of normal saline solution
immediately after a specimen for cytological examination (for a
smear or CytoTrap preparation) has been expelled from the needle.
Calcitonin levels are measured in the needle wash.
Reference Values
An interpretive report will be provided.
Cautions
Blood contamination during the biopsy might lead to false elevations of calcitonin in the fine-needle aspiration biopsy washout if serum calcitonin is significantly elevated. If blood was present in the washout, only calcitonin values significantly higher than the serum should be considered as true positives.
Immunometric assays can, in rare occasions, be subject to interferences such as "hooking" at very high analyte concentrations (false-low results) and heterophilic antibody interference (false-high results). If the clinical picture does not fit the laboratory result, these possibilities should be considered.
Results are dependent on accurate sampling and a maximum needle wash volume of ≤1.5 mL.
While the needle washes from several distinct needle passes or aspirations from a single area should be pooled, biopsies from different areas should be submitted as separate specimens.
Day(s) Performed
Monday through Friday; 6 a.m.-12 a.m., Saturday; 6:30 a.m.-5 p.m.
Report Available
Same day/1 dayPerforming Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
82308