Overview
Breast Fine Needle Aspiration (FNAC) is a minimally invasive diagnostic procedure used to evaluate breast lumps and determine their nature. This technique involves using a thin needle to aspirate cellular material from breast lesions for cytological examination. Breast FNAC is particularly valuable for rapid diagnosis of breast lesions and helps distinguish between benign and malignant conditions, guiding further management decisions.
Breast FNAC is crucial for the evaluation of breast lumps, which are common findings in clinical practice. The procedure helps identify malignant lesions requiring surgical intervention while avoiding unnecessary surgery for benign conditions. It is particularly valuable in the International Academy of Cytology (IAC) Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy, which provides standardized reporting categories. The procedure is cost-effective, safe, and provides rapid results compared to core needle biopsy.
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Indications
Evaluation of palpable breast masses of any size
Lesions with suspicious mammographic or ultrasound characteristics
Evaluation of lesions in patients with family history of breast malignancy
Assessment of new lesions in patients with history of breast cancer
Evaluation of lesions showing rapid growth or change in characteristics
Assessment of axillary lymph nodes in suspected breast cancer
Contraindications
Absolute Contraindications
Relative Contraindications
📋 Equipment Checklist
Check off items as you gather them:
Pre-procedure Preparation
Patient preparation includes obtaining informed consent, reviewing coagulation parameters (platelets >50,000, INR <1.5), and ensuring the patient is not on anticoagulants. The patient should be positioned comfortably, typically supine with the arm abducted. The breast area should be cleaned with antiseptic solution. Ultrasound guidance should be arranged for non-palpable lesions or those requiring precise targeting.Step-by-Step Procedure
Step 1: Patient Positioning and Site Preparation
Position the patient supine with the arm abducted to expose the breast area. Clean the skin over the target area with antiseptic solution in a circular motion, starting from the center and moving outward. Allow the antiseptic to dry completely. Use ultrasound to identify the target lesion and mark the entry point.
⚠️ Common Mistakes to Avoid:
- Inadequate positioning leading to difficult access to the lesion
- Not allowing antiseptic to dry, which can contaminate the specimen
- Inadequate skin preparation increasing infection risk
💡 Pro Tip:
For better access to upper outer quadrant lesions, ask the patient to place their hand behind their head.
Step 2: Ultrasound Guidance Setup
Apply ultrasound gel to the breast area and use a high-frequency linear probe to visualize the target lesion. Identify the optimal approach angle and depth. Mark the entry point on the skin. Ensure the lesion is clearly visible and measure its dimensions. Document the ultrasound findings for correlation with cytology.
⚠️ Common Mistakes to Avoid:
- Not using ultrasound guidance for non-palpable lesions
- Poor ultrasound technique causing suboptimal visualization
- Inadequate documentation of ultrasound findings
💡 Pro Tip:
Use the ultrasound to identify the most cellular part of the lesion for optimal sampling.
Step 3: Needle Insertion and Aspiration
Insert the needle perpendicular to the skin surface and advance it toward the lesion under ultrasound guidance. Once the needle tip is within the lesion, apply negative pressure by pulling back the plunger to the 10-15 mL mark. Move the needle back and forth within the lesion in a fanning motion (5-10 passes) to sample different areas.
⚠️ Common Mistakes to Avoid:
- Inserting the needle too deep and passing through the lesion
- Insufficient negative pressure causing inadequate cellularity
- Too few passes resulting in poor sampling
💡 Pro Tip:
The "non-aspiration" technique (using capillary action without suction) often yields less bloody samples with adequate cellularity for breast lesions.
Step 4: Specimen Collection and Processing
Release the negative pressure before withdrawing the needle to prevent aspiration of cells into the syringe. Withdraw the needle swiftly and immediately express the aspirated material onto labeled glass slides. Prepare smears using the "pull-apart" technique. For bloody specimens, use the "squash" technique.
⚠️ Common Mistakes to Avoid:
- Withdrawing needle without releasing pressure, losing specimen in syringe
- Delayed processing causing clotting of the aspirate
- Inadequate labeling leading to specimen mix-ups
💡 Pro Tip:
Prepare both air-dried and alcohol-fixed smears for optimal morphological evaluation and special stains.
Step 5: Multiple Passes and Adequacy Assessment
Perform 2-3 additional passes from different areas of the lesion to ensure adequate sampling. For large lesions, sample from the periphery and center. For cystic lesions, aspirate the fluid first, then sample any residual solid component. Assess adequacy by examining the slides under a microscope if available.
⚠️ Common Mistakes to Avoid:
- Insufficient passes causing inadequate sampling
- Not sampling different areas of large lesions
- Missing solid component in cystic lesions
💡 Pro Tip:
Adequacy criteria for breast FNAC require at least 6 groups of well-preserved epithelial cells with 10 cells per group.
Step 6: Fixation and Staining
Immediately fix the smears by either immersing in 95% ethanol (wet fixation) or using spray fixative held 25-30 cm from the slide (air-dried for Romanowsky stains). Label slides with patient details, site, and date. Prepare additional slides for special stains if indicated.
⚠️ Common Mistakes to Avoid:
- Delayed fixation causing air-drying artifacts in alcohol-fixed smears
- Spray fixative too close causing cell distortion
- Inadequate labeling leading to specimen mix-ups
💡 Pro Tip:
Prepare two sets of slides: alcohol-fixed for Papanicolaou stain and air-dried for May-Grünwald-Giemsa stain.
Step 7: Post-procedure Care and Documentation
Apply firm pressure to the puncture site for 5-10 minutes using sterile gauze. Check for adequate hemostasis before applying a sterile dressing. Document the procedure including the number of passes, needle gauge used, and gross appearance of aspirate. Provide post-procedure instructions to the patient.
⚠️ Common Mistakes to Avoid:
- Insufficient pressure application leading to hematoma formation
- Inadequate documentation of the procedure
- Not providing clear post-procedure instructions
💡 Pro Tip:
Patients should be observed for at least 15 minutes post-procedure to monitor for complications.
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Post-procedure Care
Post-procedure care involves applying pressure to the puncture site for 5-10 minutes to prevent hematoma formation. Patients should be observed for 15-30 minutes for any immediate complications. Instructions include keeping the site clean and dry for 24 hours, watching for signs of infection or excessive bleeding, and returning for results discussion. Most patients can resume normal activities immediately.Complications & Management
| Complication | Incidence | Signs | Management | Prevention |
|---|---|---|---|---|
| Hematoma | 2-5% | Swelling, pain, discoloration at puncture site | Apply firm pressure for 10-15 minutes, ice pack, observation | Adequate pressure post-procedure, correct coagulation parameters |
| Vasovagal reaction | 0.5-1% | Dizziness, sweating, bradycardia, hypotension | Trendelenburg position, monitor vitals, IV fluids if severe | Perform procedure with patient lying down, calm environment |
| Infection | <0.1% | Erythema, warmth, purulent discharge after 24-48 hours | Antibiotics based on culture, local wound care | Strict aseptic technique, avoid aspirating through infected skin |
| Needle tract seeding | <0.01% | Nodules along needle tract (weeks to months later) | Surgical excision of tract if occurs | Minimize number of passes, avoid FNAC in certain tumors |
| Inadequate sampling | 5-15% | Insufficient cellularity for diagnosis | Repeat FNAC after 3-6 months | Proper technique, adequate number of passes, ultrasound guidance |
Clinical Pearls
The "non-aspiration" technique (using capillary action without suction) often yields less bloody samples with adequate cellularity for breast lesions.
Always use ultrasound guidance for non-palpable lesions or those requiring precise targeting to improve adequacy rates.
For cystic lesions, completely evacuate the fluid and re-aspirate any residual solid component for better diagnostic yield.
Rapid on-site evaluation (ROSE) by a cytopathologist significantly improves adequacy rates and reduces need for repeat procedures.
Document the number of passes, needle gauge used, and gross appearance of aspirate in your procedure note.
The quality of smear preparation is as important as the aspiration technique - poor smears from good aspirates lead to non-diagnostic results.
Be aware of the IAC Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy - it provides standardized categories that correlate with malignancy risk.