Fine Needle Aspiration Cytology

Use a small gauge (eg, 25-g or 22-g) needle to avoid dilution with blood. Immobilize the palpable mass with your nondominant hand. Using a syringe holder will allow you to keep your nondominant hand on the mass. Insert the needle into the mass and pull back on the syringe plunger, creating negative pressure, using it as a cutting tool. Make short 5 mm “in-and-out” motions until you see material coming into the hub of the needle. When you start to see material in the hub, stop, release negative pressure on the syringe, and pull out to make the slides. Do not aspirate material into the syringe or dilute with blood or saline. This interferes with making good direct smears. (See preparation of slides below.) If you do not see any material at all in the hub or syringe, continue the short 5 mm strokes until you have done 15 to 20 strokes. Pull out and attempt to express material on slides (see below). Repeat the above procedure again using a clean needle for a second pass (and more passes if needed). Many physicians use no local anesthesia. If you decide to give a local, please avoid aspirating the local anesthetic into the needle. It will dilute as well as distort the specimen.

Making direct smears (preferred method):

• Using a graphite pencil, label 8 to 10 slides with the patient's name before starting the procedure.

• After aspiration, make sure to have positive pressure in the syringe (if need be, remove the needle, pull back the plunger, then reattach the needle to gain positive pressure). Avoid aspirating the material from the needle into the syringe.

• Touch the end of the needle to the end of the glass slide and express one to two drops of material. (If too much material is expressed, the slides will be too thick for optimal interpretation. A thin monolayer of cells is desired.)

• Place a second slide on top of the first, allowing the drop to spread, then gently pull slides apart toward opposite end. Fix immediately in 95% ethyl alcohol. Note: It is imperative to fix the slides immediately to avoid air drying. Continue making more slides in this fashion until all the material in the needle is used.

• Do not discard the needle yet. Rinse the needle in a labeled container of balanced salt solution and an equal volume of 50% ethanol. Send all material to the lab.

Alternative to making direct smears (less desirable, but acceptable): Express the specimen directly into a balanced salt solution and an equal volume of either 50% ethyl alcohol or Saccomanno fixative. Send to the laboratory for slide preparation.

If a cyst is aspirated, use the alternative method outlined above. The laboratory will spin the specimen for concentration.