CYTOPATHOLOGY

Fine Needle Aspiration (FNA) Technique: Fine needle aspirations are most commonly performed on breast lesions but are also useful for evaluation of many soft tissue masses, thyroid nodules and prostate. The degree of diagnostic certainty varies with site, specimen adequacy, and pathologist's experience. The technique of making a fine needle aspirate involves insertion of a 22 guage needle into the tissue without applying suction until the needle is positioned. Set plunger of syringe at 1 to 3 cc of airspace before inserting into tissue. Suction is then applied by pulling back on the syringe plunger. The needle is rapidly moved about in a plunging motion in the area of concern without withdrawing the needle tip out of the tissue. The suction is released before the needle is withdrawn. After withdrawing the needle, make smears by gently forcing the plunger down to express a drop or two of fluid and prepare as illustrated below. IMPORTANT: If the site is thyroid or salivary gland, it is helpful to make 1 or 2 air dried (not fixed) slides in addition to the fixed slides. Label slides as air dried. After smears are made, the needle and syringe may be rinsed with a small amount of liquid fixative or saline and submitted for examination.

NOTE: Step-by-step FNA instructions are available upon request.

SQUASH TECHNIQUE

1. Express a droplet of aspirate in the middle of a clean glass slide.

2. Place a second glass slide on top of the first, allowing the droplet to "spread" due to the weight of the second slide.

3. Separate slides VERTICALLY. Do not make a "pull smear." Promptly fix bothfix both slides by immersing in 95% ETOH. Alternately, slide may be generously sprayed with cyto fixative.

If the specimen is heterogeneous or contains minute tissue particles, either a "PULL TECHNIQUE" or "SQUASH TECHNIQUE" may be used. In both cases, rapid immersion and fixation is essential. The preferred fixative is 95% ETOH in a Coplin jar or other container. The smears must remain in the fixative and transported in the fixative to our lab. A less optimal technique is to spray smears immediately with fixative the same as a Pap smear is handled.

PULL TECHNIQUE

1. Express a small droplet of aspirate close to the frosted end of the slide.

2. Grasp the frosted end between the thumb and forefinger of the left hand. Support the underside of the slide with the left 4th and 5th fingers. Using the right hand, place the "near" edge of the spreader slide across the mid portion of the slide, rotating the "far" edge down, covering the droplet.

3. Without raising the spreader slide or putting pressure on the spreader, pull the spreader down the slide. Surface tension is sufficient to make a smear as the slide is pulled. A good smear should have a flame shape. Fix IMMEDIATELY in 95% ETOH. Note: This entire technique should only take a few seconds.

All slides must be labeled with the patient's name and sent with a request form.