What is the recommended treatment for an infected breast cyst?

Management of Infected Breast Cysts

The recommended treatment for an infected breast cyst is incision and drainage followed by appropriate antibiotic therapy, with complete evacuation of pus necessary for larger infected cysts or abscesses. 1

Diagnosis and Assessment

• Infected breast cysts typically present with:

  • Rapid onset of breast erythema, edema, warmth
  • Pain and tenderness
  • Possible palpable mass
  • Systemic symptoms (fever, malaise) in more severe cases

• Ultrasound is the first-line imaging modality for evaluating breast cysts and confirming infection 1

  • Can differentiate between simple inflammation and abscess formation
  • Helps guide therapeutic intervention

Treatment Algorithm

Step 1: Initial Management

• For infected cysts with abscess formation:

  • Incision and drainage is the recommended primary treatment 2, 1
  • Complete evacuation of pus is necessary for larger infected cysts 1

• For smaller infected cysts:

  • Ultrasound-guided aspiration may be sufficient 3, 4
  • Serial aspirations may be required for complete resolution 4

Step 2: Antibiotic Therapy

• Systemic antibiotics should be initiated to cover common breast infection pathogens:

  • First-line: Cephalexin or dicloxacillin (to cover S. aureus) 2
  • If MRSA suspected: Clindamycin, doxycycline, or trimethoprim-sulfamethoxazole 2
  • For more severe infections: Consider adding metronidazole for anaerobic coverage 2

• Duration of antibiotic therapy:

  • Typically 7-10 days
  • May need to be extended based on clinical response

Step 3: Follow-up

• Clinical assessment within 48-72 hours after initial treatment to assess response 1
• Repeat ultrasound may be necessary to ensure complete resolution
• If no improvement or worsening despite treatment:
  • Consider repeat drainage
  • Reassess antibiotic coverage
  • Rule out underlying malignancy with core biopsy 2

Special Considerations

Aspiration vs. Incision and Drainage

• Ultrasound-guided aspiration with local antibiotic injection has shown success rates of up to 96% in some studies 4

• Benefits of aspiration over surgical drainage:

  • Less invasive
  • Better cosmetic outcome
  • Can be performed in outpatient setting
  • Lower cost 4

• However, incision and drainage is preferred for:

  • Larger abscesses
  • Multiple loculations
  • Failed aspiration attempts
  • Severe infection

Diagnostic Considerations

• Always obtain samples for culture during drainage to guide antibiotic therapy 2
• If bloody fluid is obtained during aspiration, cytological examination should be performed 1
• Consider core biopsy if:
  • Infection recurs after appropriate treatment
  • Underlying mass persists after resolution of infection
  • Complex cystic features are present (higher risk of malignancy 14-23%) 2, 1

Pitfalls and Caveats

• Failure to distinguish between simple inflammation and abscess formation can lead to inappropriate treatment
• Incomplete drainage may result in recurrence
• Underlying malignancy can occasionally present with inflammatory features
• Antibiotics alone are insufficient for treatment of established breast abscesses 2, 3
• Recurrent infections may indicate the need for more extensive evaluation, including MRI and possible excisional biopsy

By following this structured approach to infected breast cysts, clinicians can achieve optimal outcomes while minimizing complications and recurrence.