What is the latest management algorithm for granulomatous mastitis?

Management Algorithm for Granulomatous Mastitis

Corticosteroids are the first-line treatment for idiopathic granulomatous mastitis, with surgical excision reserved for steroid-resistant cases or recurrences. 1, 2, 3

Diagnosis

1. Clinical Presentation:

   • Unilateral, sometimes painful breast mass or resistance
   • Hard, irregular mass that can mimic breast cancer
   • Skin changes including erythema (29% of cases) 4
   • Most common in women of childbearing age (median age 34-36 years) 4, 5

2. Diagnostic Workup:

   • Ultrasonography: Most useful initial imaging (typically shows hypoechoic mass/abscess) 1, 5
   • Mammography: May show non-specific mass 5
   • MRI: May show heterogeneous non-mass contrast enhancement 5
   • Definitive diagnosis requires tissue sampling:
     • Core needle biopsy or incisional biopsy (both used with equal frequency, 37% each) 4
     • Histopathology: Non-caseating granulomas, often with microabscesses and fistula formation 1
     • Special stains to rule out infectious causes (tuberculosis, fungi) 5

3. Differential Diagnosis:

   • Breast cancer
   • Infectious mastitis (bacterial, tuberculosis)
   • Sarcoidosis
   • Foreign body reaction
   • Other granulomatous diseases (syphilis, rhinoscleroma, GPA, EGPA) 6

Treatment Algorithm

Step 1: Initial Management

• First-line: Oral corticosteroids
  • Initial dosage: 0.5-1 mg/kg/day of prednisone 3
  • Duration: 4-6 weeks followed by slow taper over 1-3 months
  • Success rate: 42% with steroids alone 2

Step 2: For Steroid-Resistant Cases

• Surgical excision:
  • Wide local excision with negative margins
  • Success rate: 79% with partial mastectomy 2
  • Thorough excision of inflammatory tissue is crucial 1
  • May require reconstructive breast surgery techniques 1

Step 3: For Recurrent Disease

• Options include:
  • Repeat steroid course
  • More extensive surgical excision
  • Combined approach (surgery followed by steroids)
  • In severe recalcitrant cases: total mastectomy (100% success rate but rarely needed) 2

Step 4: Adjunctive Treatments

• Antibiotics: Only if secondary infection is present
• Immunosuppressive agents: For steroid-resistant cases
  • Methotrexate
  • Azathioprine
• Observation: May be appropriate for mild cases (56% success rate) 2

Follow-up and Monitoring

• Regular clinical follow-up every 1-3 months during active treatment
• Long-term follow-up essential due to high recurrence rate (up to 50%) 1
• Repeat imaging as clinically indicated

Special Considerations

1. Exclude infectious causes before starting steroids:

   • Tuberculosis testing (tuberculin/PCR)
   • Microbiological cultures
   • Special stains on biopsy (EZN for acid-fast bacilli, gram stain) 5

2. Pregnancy and lactation:

   • May exacerbate condition
   • Careful consideration of steroid use during pregnancy/lactation
   • Lactational changes seen in 6.1% of cases 5

3. Immunocompromised patients:

   • Higher risk of infectious etiology
   • HIV-positive patients represented 29% in one large series 4

Pitfalls to Avoid

1. Delayed diagnosis: Median time from symptoms to diagnosis is 73 days 4
2. Inadequate biopsy: Small, superficial trucut biopsies may cause difficulties in determining etiology 5
3. Misdiagnosis as breast cancer: Clinical and radiographic features can mimic malignancy
4. Insufficient surgical margins: Associated with higher recurrence rates 1
5. Premature discontinuation of steroids: Gradual tapering is essential to prevent recurrence

The management of granulomatous mastitis remains challenging with high recurrence rates. A multidisciplinary approach involving surgeons, pathologists, and radiologists is crucial for optimal management 5. While conservative treatment with corticosteroids should be attempted first, surgical excision provides higher success rates for persistent or recurrent disease.