Fine Needle Aspiration Cytology or FNA

Over the past few years, Fine Although Needle Aspiration Cytology or FNA has been used extensively as a mean to establish a histological diagnosis for suspicious breast masses. Although, most surgeons use this technique for palpable breast masses, it is also used for suspicious mammographic lesions.

Concept:

The concept of this procedure is to capture a few representative cells of the identified breast lesion in the aspirate to obtain an accurate histological diagnosis..

Problems inherent to this technique

• Insufficient Specimen: One of the major draw back of this technique is to obtain an insufficient specimen. The rate of insufficient specimen varies from 2 to 36%.
• Reported Sensitivity ranges from 68 to 100% and the specificity from 2 to 36%.
• General Inability to differentiate In-situ from Invasive Carcinoma.

Technique

A specially designed Gun-Syringe can be used. Most surgeons will use one or several 10 cc luer-lock syringes with a long 20 G needle.

• Step 1: Identifying the Lesion and finding the best entry site or access.

• Step 2: The FNA: No local anesthetic agent is used. The breast is held under tension. The surgeon will insert the needle and will repetitively pass through the lesion. Simultaneously, negative pressure is applied as soon as the needle enter the skin. The pressure is released immediately prior to removing the needle from the breast. The same maneuver is repeated.This maneuver is usually repeated twice (using two different needles and syringes).

• Step 3: Collecting the specimen and Preparing the Slides:

1. Label Slides: Mark all the submitted slides or fluids with patients name. If several sites are aspirated, indicate site on slide.

2. Place small amount of material on the slides: Prepare smears using a small amount of material and as little blood as possible.

3. Prepare smears: If possible prepare at least 6 slides. We recommend fixing half and leaving the other half air-dried. Slides need to be fixed immediately after preparation by either of two methods: 1. Immerse slides in 95 % alcohol; paper clip on the frosted end will keep the slides apart in the jar; or (2) spray the slides with cytology fixative (e.g. Pro-Fixx). Place all slides in blue slide holders for transport.

4. If the specimen is unsuitable for the preparation of smears (e.g.,cyst contents), express the syringe contents into the smaller jar containing Saccomano fixative.

• Step 4: Applying Pressure: Pressure is applied to minimize the post-operative hematoma.

• Step 5: Staining for FNA.

A. Airdryed smears are stained with Diff-Quick Stain as follows:

1. Fixative 20 seconds

2. Staining solution I: 20 seconds

3. Staining solution II: 20 seconds

4. Distilled water: 10 seconds

5. 95 % Ethyl alcohol: 10 seconds

6. Absolute alcohol: 15 seconds

7. Xylene: 15-20 seconds

B. Alcohol Fixed Smears stained with Papanicolaou Stain

C. Needle rinse is prepared for CELL BLOCK and stained with H&E Stain.

References:

• Jakson VP et al.: Stereotactic fine-needle aspiration biopsy for non palpable breast lesions. AJR Am J Roentgenol 1990:154:1196-1197
• Massod S: Occult breast lesions and aspiration biopsy: A new challenge. Daign Cytopathol 1993:9:613-614.