Breast: Mastitis & Abscess

Mastitis & Abscess

Definitions

  • Mastitis: Mammary Gland Inflammation
    • Lactational (Puerperal) Mastitis: Mastitis Associated with Breastfeeding (Most Common)
      • Most Common in the First Three Months
    • Periductal Mastitis (Ductal Ectasia): Inflammation of the Subareolar Ducts with Ductal Dilation, Obstruction & Filling with Fluid
      • Usually Causes a Chronic Inflammation
  • Breast Abscess: Purulent Fluid-Filled Cavity of the Breast

Microbiology

  • Staphylococcus aureus – Most Common Organism
  • Other Organisms:
    • Streptococci
    • Enterococci
    • Bacteroides

Causes

  • Lactational Mastitis:
    • Partial Duct Blockage
    • Milk Overproduction
    • Infrequent Feedings
    • Rapid Weaning
    • Nipple Trauma
  • Periductal Mastitis (Ductal Ectasia):
    • Not Entirely Certain
    • Obstruction – Debated
    • Risk Factors: Smoking & Piercings
  • Breast Abscess
    • Primary: No Inciting Disease
    • Secondary: Preexisting Mastitis or Cellulitis

Presentation

  • Pain
  • Swelling
  • Erythema
  • Fever
  • Periductal Mastitis Can Cause Green-Brown Creamy Nipple Discharge (Most Common Cause)
  • Abscess Can Have a Palpable Fluctuant Mass

Diagnosis

  • Clinical Diagnosis
  • May Consider Breast Milk Culture to Guide Antibiotic Therapy
  • Consider US to Evaluate for Abscess if Fails to Improve Over 48-72 Hours

Treatment

  • Mastitis:
    • Initial Treatment: NSAID’s & Cold Compress
    • If Infective/Beyond 12-24 Hours: Antibiotic Therapy
      • Primary Antibiotics: Dicloxacillin or Cephalexin
        • Consider Amoxicillin-Clavulanate (Augmentin) for Periductal Mastitis
      • If at Risk for MRSA: Trimethoprim-Sulfamethoxazole (TMP-SMX/Bactrim)
      • If Severe or Systemic: IV Vancomycin
    • Continue Feeding & Promote Complete Emptying (Pumping or Hand Expression if Needed)
  • Abscess: Antibiotics & Drainage
    • Antibiotics: Similar to Mastitis
    • Drainage:
      • Preferred Method: Needle Aspiration (Most Resolve After 2-3 Aspirations)
        • I&D Can Cause Mammary Duct Fistula or Milk Fistula
      • Indications for Incision & Drainage (I&D):
        • Refractory
        • Multiloculated
        • Recurrent Abscess
        • Skin Compromised (Ischemia or Necrosis)
    • Continue Feeding & Promote Complete Emptying
      • Although Bacteria are Present in Milk, No Harm is Done to the Infant
      • If Too Painful: Consider Pumping or Hand Expression with Feeding on the Unaffected Side
  • If Treatments Continue to Fail: Consider Skin Biopsy for Inflammatory Breast Cancer

Mastitis 1

Breast Abscess on US 2

Granulomatous Mastitis

Basics

  • Definition: Rare Benign Inflammatory Disease of the Breast Causing Granulomas
  • Causes:
    • Idiopathic – May Be Associated with Corynebacterium kroppenstedtii
    • Tuberculosis (TB)
    • Sarcoidosis

Presentation

  • Peripheral Inflammatory Breast Mass
  • May Have Abscess or Overlying Skin Inflammation/Ulceration

Diagnosis

  • Initial Imaging: US
  • Diagnosis: Core Needle Biopsy (CNB)
    • Pathology: Non-Necrotizing Granulomatous Lesions Centered on a Breast Lobule
    • Send for Acid-Fast Stains & Culture (Rule Out TB)

Treatment

  • Primary Treatment: Conservative Management
    • Treat Mastitis or Abscess as Indicated
  • For Tuberculosis: Typical TB “RIPE” Antibiotic Regimen (Rifampin, Isoniazid, Pyrazinamide & Ethambutol)

Granulomatous Mastitis on MRI 3

References

  1. Lut J. Wikimedia Commons. (License: CC BY-SA-4.0)
  2. di Summa PG, Yvon A, Larcher L, Raffoul W, Koch N. Propionibacterium avidum infection following breast reduction: high morbidity from a low-virulence pathogen. J Surg Case Rep. 2015 Feb 10;2015(2):rjv002. (License: CC BY-NC-4.0)
  3. Bilal A, Badar Albadar F, Bashir Barlas N. Granulomatous Mastitis: Imaging of Temporal Evolution. Scientifica (Cairo). 2016;2016:3737528. (License: CC BY-4.0)