What is the recommended treatment for an infected breast cyst?

Treatment of Infected Breast Cysts

The recommended treatment for an infected breast cyst includes incision and drainage followed by appropriate antibiotic therapy, with ultrasound-guided aspiration being an effective alternative to surgical drainage in many cases.

Diagnosis

Before initiating treatment, proper diagnosis is essential:

• Ultrasound imaging is the first-line imaging modality for evaluating breast cysts 1
• Infected cysts typically present with:
  • Pain, tenderness, and erythema
  • Fluctuant mass with surrounding cellulitis
  • Systemic symptoms (fever, malaise) in more severe cases

Treatment Algorithm

Step 1: Drainage Procedure

• Primary intervention: Incision and drainage

  • For larger infected cysts or abscesses, complete evacuation of pus is necessary 2
  • Break up loculations within the cavity to ensure complete drainage
  • Send specimen for Gram stain and culture to guide antibiotic therapy 2

• Alternative approach: Ultrasound-guided aspiration

  • Particularly effective for smaller or well-defined collections
  • May require serial aspirations (weekly until resolution) 3
  • Consider local antibiotic injection after aspiration 3
  • Less invasive than surgical drainage with comparable efficacy

Step 2: Antibiotic Therapy

• Initial empiric therapy (pending culture results):

  • For mild to moderate infections: Oral antibiotics with MRSA coverage
    • Trimethoprim-sulfamethoxazole, doxycycline, or clindamycin 2
  • For severe infections or systemic symptoms:
    • Vancomycin or linezolid (for MRSA coverage)
    • Consider adding coverage for Gram-negative organisms in healthcare-associated infections 4

• Culture-directed therapy:

  • Adjust antibiotics based on culture and sensitivity results
  • Duration typically 7-14 days depending on clinical response

Step 3: Wound Management

• Simple dressing changes are usually sufficient after drainage 2
• Some clinicians pack the cavity with gauze to prevent premature closure
• Follow-up within 48-72 hours to assess response to treatment

Special Considerations

1. Staphylococcus aureus is a common pathogen in breast infections:

   • 67% of breast implant infections are caused by S. aureus 5
   • Of these, up to 68% may be MRSA infections 5
   • This supports empiric MRSA coverage while awaiting culture results

2. Recurrent infections may require:

   • Complete surgical excision of the cyst
   • Evaluation for underlying conditions
   • Longer antibiotic courses

3. Lactating women with infected cysts:

   • Continue breastfeeding if possible 1
   • Choose antibiotics compatible with breastfeeding

4. Unusual pathogens should be considered in specific circumstances:

   • Hydatid cysts in endemic areas 6
   • Gram-negative organisms in healthcare-associated infections 4

Follow-up

• Clinical assessment within 48-72 hours after initial treatment
• Ultrasound follow-up at 1,4, and 12 weeks after clinical resolution 3
• Consider biopsy if:
  • Fluid is bloody
  • Residual mass persists after aspiration
  • Cyst increases in size during follow-up 1

Pitfalls to Avoid

1. Inadequate drainage leading to persistent infection
2. Narrow-spectrum antibiotics that fail to cover likely pathogens
3. Failure to obtain cultures before initiating antibiotics
4. Premature discontinuation of antibiotics before complete resolution
5. Missing underlying malignancy (always send specimens for pathology)

By following this approach, most infected breast cysts can be effectively treated with minimal morbidity and good cosmetic outcomes.