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Test ID: CATLN Calcitonin, Fine-Needle Aspiration Biopsy Needle Wash, Lymph Node

Reporting Name

Calcitonin, FNAB, 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

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 less than 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-positive results.


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.


In athyrotic patients with a history of medullary thyroid carcinoma, a fine-needle aspiration calcitonin value of 5.0 pg/mL and greater is suggestive of the presence of metastatic MTC in the biopsied lymph node.


Calcitonin values less than 5.0 pg/mL suggest the lymph node does not contain medullary thyroid carcinoma. This result is dependent on accurate sampling and a total needle wash volume between 0.5 to 1.5 mL.


This test should be interpreted in the context of the clinical presentation, imaging, and cytology findings. If the results are discordant with the clinical presentation, a sampling error at the time of biopsy should be considered.

Report Available

1 to 3 days

Day(s) Performed

Monday through Saturday

Clinical Reference

1. Trimboli P, Rossi F, Baldelli R, et al: Measuring calcitonin in washout of the needle in patients undergoing fine needle aspiration with suspicious medullary thyroid cancer. Diagn Cytopathol. 2012 May;40(5):394-398

2. Boi F, Maurelli I, Pinna G, et al: Calcitonin measurement in wash-out fluid from fine needle aspiration of neck masses in patients with primary and metastatic medullary thyroid carcinoma. J Clin Endocrinol Metab. 2007 Jun;92(6):2115-2118

3. Kudo T, Miyauchi A, Ito Y, Takamura Y, Amino N, Hirokawa M: Diagnosis of medullary thyroid carcinoma by calcitonin measurement in fine-needle aspiration biopsy specimens. Thyroid. 2007 Jul;17(7):635-638

4. Trimboli P, D’Aurizio F, Tozzoli R, Giovanella L: Measurement of thyroglobulin, calcitonin, and PTH in FNA washout fluids. Clin Chem Lab Med. 2017 Jun;55(7):914-925

Method Name

Electrochemiluminescence Immunoassay

Specimen Type

Fine Needle Wash

Shipping Instructions

Send specimen frozen.

Necessary Information

The biopsied site of each specimen is required and must be clearly identified in the LIS and/or batch sheet.

Specimen Required

Patient Preparation: For 12 hours before this procedure do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.

Container/Tube: Plain, plastic, screw-top tube

Specimen Volume: 1 to 1.5 mL

Collection Instructions:

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 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. (If more than 1 site is biopsied, see Additional Information)

7. 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.

8. Freeze within 2 to 4 hours of collection.

Additional Information:

1. If more than 1 site is biopsied, each washing material should be submitted on a separate tube and under a different order number.

2. 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.

3. Do not send saline control. This test has been validated to rule-out saline matrix effect.

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Fine Needle Wash Frozen (preferred) 7 days
  Refrigerated  4 hours

Reference Values

An interpretive report will be provided.

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
CATLN Calcitonin, FNAB, Lymph Node 75709-6


Result ID Test Result Name Result LOINC Value
CATL Calcitonin, FNAB, Lymph Node 75709-6
SITEB Site 39111-0


If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.

Mayo Clinic Laboratories | Endocrinology Catalog Additional Information:

mml-endo-thyroid, mml-adrenal-gonad-pituitary