Cytopathology: Fine Needle Aspiration (FNA)

CPT Code(s):

88173; this CPT code may also be reported in conjunction with aspiration of the specimen (10021) and/or immediate on-site evaluation of the specimen (88172). Additional CPT codes, such as 88106, 88108 and/or 88305, may be reported, depending on the preparation methods.

Specimen Requirements:

Collection: FNA kits (#0099) may be obtained by calling UF Health Pathology Laboratories’ Client Services Department at 888.375.LABS (5227).

FNA Procedure:

  1. Sterile technique must be used on all patients. Gloves should always be worn for personal safety.
  2. FNA specimens may be submitted as smeared slides or fluid specimens made by rinsing the needle and syringe in PreservCyt® or SurePath™ fluid.
  3. While maintaining aseptic conditions, the contents of the syringe and needle are partially expelled onto a glass slide, which is appropriately labeled with the patient’s name and the number of the pass on its frosted side. Working quickly, the specimen should be gently smeared between two slides by lightly sandwiching them together (do not compress) and then separating them as if opening a book.
  4. Immediately fix one Superfrost Plus slide in 95% ETOH with 2% acetic acid for each pass. All specimens must be fixed for at least 15 minutes before staining to preserve cellular morphology.
  5. All other slides (plain slides) are air dried and immediately stained by the modified Giemsa (e.g.: Diff-Quik) method and may be screened by the aspirator for immediate assessment.
  6. The remaining material in the needle should be rinsed in a preservative fluid.
  7. If fixed smears are received, these are usually stained with Pap stain unless there is a request for special stains.
  8. If a fluid specimen is received, one Pap (plus) and one Diff-Quik (plain) slide should be prepared from each fluid specimen unless special stains are required. I. Discuss requests for special stains with a pathologist.
  9. Specimens from different sites should never be combined.
  10. Specimens must be in clean containers to avoid contamination.
  11. Collection errors or problems may compromise the results by obscuring cellular morphology.
Storage/Transport Temperature:

  • Unacceptable Conditions:
    • Air drying
    • Excessively thick smears
    • Excessively bloody samples
Stability (collection to initiation of testing):

  • Ambient:
    • Slides: Indefinitely
    • CytoLyt®: 3 weeks
    • ThinPrep®: 3 weeks
    • SurePath™: 4 weeks
Acceptable specimens include:

  1. Smeared slides fixed in 95% ethyl alcohol + 2% acetic acid on Superfrost Plus slides (preferred);
  2. Smeared slides fixed in methanol (preferred);
  3. Smeared slides fixed with a spray fixative, such as Profix;
  4. Air-dried smears for Diff-Quik stain on plain slides;
  5. Cystic masses may be drained and the cyst content submitted for cytologic evaluation; or
  6. Material in PreservCyt® or SurePath™ fixatives or other special study preservative.

Adequacy Procedure: UF Health Pathology Laboratories prefers to receive specimens as prepared slides; however, if the clinician performing the adequacy procedure lacks the proper supplies, a needle rinse must be rushed to the lab and should be refrigerated unless it is in CytoLyt®.

If supplies are needed, UF Health Pathology Laboratories can be contacted to provide these prior to scheduling the FNA. Specimens should be submitted as paired slides (air-dried and alcohol-fixed). If specimens are submitted as needle rinse only, the sensitivity/specificity of the test may be impaired.

If alcohol-fixed smears are received, they are typically stained with Pap stain, unless there is a request for special stains. If they are air-dried, a modified Giemsa stain will be used. If you have any questions about this procedure, check with UF Health Pathology Laboratories before staining. Document any requests for special stains on the requisition form. Specimens from different mass sites should never be combined.

Slide Preparation for Adequacy:

  1. Following the FNA, gently remove the needle from the syringe while holding the needle above the slide in case of accidental spillage of the specimen.
  2. Draw air into the syringe and replace the needle onto the syringe.
  3. Squirt only 1 – 2 drops to the center of one of the labeled slides.
  4. Place the labeled slide face down on the other slide and let the specimen slowly spread out between the two slides. Do not press the two slides together. Place the needle and syringe into the CytoLyt® needle rinse tube or RPMI and draw in some fluid.
  5. Quickly separate the two slides like opening a book. The result will be a mirror-image of the specimen on each slide.
  6. Immediately fix one slide in 95% ETOH (ethanol; the green-top slide holder). Allow the other slide to air-dry. Return to the syringe and needle and gently flush the needle in the solution 2 – 3 times. Then, place the needle in an appropriate sharps disposal container.
  7. The other air-dried slide should now be stained by immediately using the Diff-Quick staining method, so it can be reviewed for adequacy. The Diff-Quick staining method should be performed as follows:
    • Greenish-Blue QuickLink III Fixative (Methanol): Dip the slide in the greenish-blue methanol fixative 20 times.
    • Dark Orange QuickLink III Solution I (Sodium Azide): Dip the slide in the dark orange sodium azide solution 20 times.
    • Dark Blue QuickLink III Solution II (Hematoxylin): Dip the slide in the dark blue hematoxylin solution 20 times.
    • Water: Dip the slide in the water 20 times to rinse it.
  8. After the slide has been stained and air-dried, view the slide with a microscope. If the stained slide is adequate (cellular material of target organ present), it is ready to be packaged and returned to UF Health Pathology Laboratories. If the slide is inadequate (blood or fat only), you must repeat this entire procedure, beginning with step 1 of the FNA Procedure.
  9. Repeat the adequacy process for each FNA pass on the same mass extraction site as needed (Remember to begin with a new kit, if moving to a different site, and use a separate requisition for each site.).
  10. Following meticulous adequacy reviews, place all slides and the properly labeled container into the biohazard bags and kit box with the completed requisition. Kit boxes will be retrieved by UF Health Pathology Laboratories’ courier, and the results will usually be available in 1 – 2 days.
  11. All used needles should be placed in appropriate sharps disposal containers following the preparation of the slides and rinses. Unsatisfactorily used slides are also placed in sharps containers. Other contaminated materials are placed in their proper containers respectively.
  12. Collection errors or problems may compromise the results by obscuring cellular morphology. These include:
    1. Air-drying of the slides placed in alcohol
    2. Excessively thick or crushed smears
    3. Excessively bloody samples

Note: Liquid specimens (cyst contents) must be in clean containers to avoid contamination.


Fine needle aspiration (FNA) is used as a diagnostic tool and in the follow-up of certain patients with known masses. FNAs are performed at physicians’ discretion. This procedure entails inserting a small-gauge needle, usually a 21- to 25-gauge needle, into a mass to remove a cellular sample for microscopic evaluation. The procedure should be performed by using sewing machine-like excursions, while applying minimal negative pressure (No more than 0.5 cc of suction is needed.).




1 – 5 days