Geisinger Medical Laboratories Cytopathology Specimen Collection Instructions

Fine Needle Aspiration Specimens

Fine needle aspiration of mass lesions is commonly utilized in the detection and characterization of a variety of malignant diseases. Obtaining an adequate specimen requires attention to good aspiration technique as well as to processing of material obtained.

Collection of FNA Specimens

Indications: To determine benignity or malignancy of mass lesions and to characterize the type of malignancy or benign disease which is present.

Specimen Required:

Adequate cellular material for cytologic evaluation obtained from an appropriately performed fine needle aspiration. This will depend on the specimen site and character of the lesion being aspirated. In general, this requires that there be enough material for the examiner to at least determine that the aspirating needle sampled a mass lesion.

Supplies:

3, 5, 10 or 20 mL syringe. Syringe pistol (optional). 22 to 25 gauge needle of appropriate length. Single end label clear glass slides (for preparation of direct smears). Fixative to preserve fixed slides (either Cytology spray fixative, Saccomanno fixative or 95% ethyl alcohol in coplin jar). RPMI 1640 medium should be used to submit remaining aspirated material for additional studies.).

Collection Procedure:

Please note that the following collection procedure is a suggested guideline. Aspiration techniques vary widely based on personal preference, and specific clinical circumstances must be taken into account when deciding on the method of aspiration utilized.

NOTE:  If collecting FNA for flow cytometry studies, please refer to the T&B cell markers collection guidelines for storage and transport information.

Identification and Localization of a Mass Lesion

Mass lesions usually come to attention either by simple identification of the development of a mass (usually superficially) or by the development of symptoms directly or indirectly caused by the mass. In order to be able to sample the identified lesions, some means of accurate localization must be available

Patient Preparation

For superficial aspirates, clean technique suffices for cleansing of the skin surface. Local anesthetic may or may not be used. If more than two or three attempts are anticipated, this is recommended. However, be certain not to contaminate the lesion with a large volume of anesthetic. Also, make attempts not to directly interfere with the ability to palpate and localize the lesion.

For deep aspirates, sterile technique is required for cleansing of the skin and local anesthetic is usually required.

Assemble the aspirating equipment. If direct smears are to be made, label the slides prior to the aspiration. With the target of aspiration fixed with the non-dominant hand between the thumb and index finger, and the syringe pistol in the dominant hand, the needle is placed against the skin. If the lesion is very superficial, the needle should approach the skin at approximately a 30 degree angle. If the mass is deep, it should approach the skin perpendicularly.

A quick motion should be used in passing the needle through the skin. The needle is then advanced through the subcutaneous tissue into the mass. If the mass is small, the needle should be aimed toward the center; if it is large, the needle should be aimed toward the periphery as the center of larger masses may be necrotic. A noticeable difference in the consistency of the tissue should be noted when the needle penetrates the mass.

With the needle in the mass, the needle tip should be moved in short motions initially to loosen cells with in the mass. Negative pressure is then applied by pulling back on the plunger of the syringe. Without releasing pressure, the needle within the target is withdrawn slightly but not out of the lesions, and then reinserted at a slightly different angle. This maneuver should be repeated several times before complete withdrawal. While redirecting the needle, a corkscrew action may be used. If blood or material appears in the hub of the needle, the aspiration should be stopped.

Prior to withdrawal of the needle, negative pressure must be released to prevent suction of the material into the barrel of the syringe when the needle exits the skin.

Apparition (Deep Lesions)

While the basic aspiration procedure is similar for deep lesions, specialized equipment for imaging, specialized needles, and setups for aspiration, and emergency equipment for handling major complications are required. Specific techniques are highly variable, according to personal preferences. While this guide will not attempt to provide methodological guidelines for aspiration of deep masses, the principles of not applying negative pressure until in the mass, stopping aspiration when blood or material appears in the hub of the needle, and not maintaining negative pressure when withdrawing the needle should be kept in mind.

Preparation of Direct Smears

For preparation of smears, single-end labeel clear glass slides should be utilized. Slides should be labeled prior to aspiration. Some author investigators recommend gently expressing a drop of aspirated fluid onto a slide, while others recommend forcefully expelling the material onto the slide. The actual method will be determined in part by the nature of the material present. If the aspirated material is abundant and fluid, a drop may be easily expressed without force. If the material is scant or more viscous or solid, the material must often be forcefully expelled. The latter method can result in splattering of material off of the slide and will utilize most of the specimen in the preparation of a minimal number of smears, necessitating more passes if additional material is required for additional studies. The former process allows for better controlling of the smear process.

Once the specimen is on the slide, it must be smeared. The simplest way to accomplish this is to oppose a second glass slide onto the first, allowing the aspirated material to provide better surface tension between the two slides, and then gently and quickly pull the two slides apart in a horizontal motion to distribute the material in a thin film over both slides.

One smear from each pass should be immediately spray-fixed or immediately dropped into a Coplin jar containing enough 95% ethyl alcohol or Saccomanno fixative to cover the specimen area of the slide.

The second slide from each pass should be allowed to air dry. The air dried slide can be stained with Diff Quick and used to provide an immediate assessment of cellularity if appropriate training has been provided (contact Cytology Laboratory).

If the material remains in the hub of the needle, additional smears may be prepared or the material may be flushed into a tube containing RPMI 1640 medium.

It is recommended that the additional aspirated material be flushed into RPMI 1640 medium for further processing by the Cytopreparatory Lab.

NOTE: Recommended collection procedure is to obtain three passes from each mass/lesion. One fixed slide and one air dried slide from each pass, remaining material to be submitted in RPMI. Perform a fourth pass to submitted in RPMI for additional studies to be performed in Cytology Laboratory. If passes are from same mass/lesion, may be submitted in single tube of RPMI. A new tube of RPMI should be used for each additional site sampled.

Submit the specimen (smears and/or material expelled into solution) to the Cytopathology Laboratory along with the completed cytology request form. Each slide should be labeled with patient identifiers (Name & MRN or Name & DOB). If location of fine needle aspiration is changed then source should be noted on slide as well.

Reviewed/revised:  1/20/2011