Mastitis in Men: Causes and Treatment
Mastitis in men is rare and typically represents non-lactational inflammatory breast disease, most commonly plasma cell mastitis or idiopathic granulomatous mastitis, requiring clinical diagnosis with imaging and biopsy to exclude malignancy, followed by anti-inflammatory treatment.
Causes of Male Mastitis
Primary Inflammatory Conditions
Plasma cell mastitis is the most common inflammatory breast disease in men, though still rare, and represents inflammation of the breast parenchyma that is often difficult to assess by clinical examination and radiological investigation alone 1
Idiopathic granulomatous mastitis can occur in men at all ages, with suspected triggers including inflammatory, infectious, and hormonal factors 2, 3
Infectious mastitis may occur but is less common than inflammatory causes, and can be caused by common skin flora including Staphylococcus and Streptococcus species 4
Secondary and Associated Conditions
Gynecomastia with inflammation should be considered in men presenting with unilateral breast enlargement and inflammation, as gynecomastia is the most common cause of breast enlargement in males 5
Hormonal disorders including hyperprolactinemia, liver cirrhosis, and Klinefelter syndrome can predispose to breast tissue changes that may become inflamed 6
Diagnostic Approach
Initial Clinical Assessment
Physical examination should assess for focal breast tenderness, overlying skin erythema, palpable masses, and differentiate true glandular tissue from fatty pseudogynecomastia 5, 4
Rule out malignancy first: Male breast cancer is rare (<1% of all breast cancers, median age 63 years) but must be excluded, especially in older men with suspicious findings 5
Imaging Algorithm
For men younger than 25 years: Ultrasound is the initial recommended imaging study if clinical findings are indeterminate or suspicious 5
For men 25 years and older: Mammography or digital breast tomosynthesis (DBT) is recommended as the initial imaging study, with mammography having 92-100% sensitivity and 90-96% specificity for male breast evaluation 5
Ultrasonography should be performed to identify abscesses in immunocompromised patients or those with worsening or recurrent symptoms 4
Tissue Diagnosis
Core needle biopsy is superior to fine-needle aspiration and is the procedure of choice for most image-detected breast lesions requiring tissue diagnosis 5
Ultrasound-guided core biopsy is preferred for lesions visible on ultrasound due to patient comfort, real-time visualization, and sampling accuracy 5
Histopathologic confirmation is essential to establish the diagnosis of granulomatous mastitis and exclude infectious or systemic etiologies 3
Treatment Algorithm
Step 1: Conservative Management (First 1-2 Days)
NSAIDs for pain and inflammation control 4
Ice application to reduce inflammation 4
Avoid aggressive interventions: Excessive pumping, heat application, and aggressive breast massage are no longer recommended as they may worsen the condition 4
Step 2: Antibiotic Therapy (If No Improvement)
Narrow-spectrum antibiotics effective against Staphylococcus aureus (e.g., dicloxacillin, cephalexin) should be prescribed if symptoms do not improve after conservative measures 7
Consider methicillin-resistant S. aureus (MRSA) coverage if the condition worsens or in areas with high MRSA prevalence 7
Obtain cultures to guide antibiotic therapy when infection is suspected 4
Most patients can be treated as outpatients with oral antibiotics 4
Intravenous antibiotics and hospital admission are required if the condition worsens or there is concern for sepsis 4
Step 3: Anti-Inflammatory Treatment for Granulomatous Mastitis
Prednisone is the initial treatment of choice for idiopathic granulomatous mastitis, used in approximately 68% of patients 3
Methotrexate (MTX) can be used either as initial treatment combined with prednisone (27% of patients) or as an alternative regimen, with approximately 55% of patients ultimately receiving MTX 3
Treatment duration: Approximately 73% of patients discontinue treatment with acceptable disease control without recurrence during follow-up 3
Corticosteroids and MTX, with or without surgery, are the treatment of choice for idiopathic granulomatous mastitis 3
Step 4: Surgical Intervention
Abscess drainage: Surgical drainage or needle aspiration is needed if breast abscess develops as a complication 7
Surgery may be considered in combination with medical therapy for refractory granulomatous mastitis 3
Important Clinical Considerations
Monitoring and Follow-Up
Recurrence rate: Approximately 14% of patients with idiopathic granulomatous mastitis experience disease recurrence 3
Adverse drug reactions occur in approximately 18% of patients treated with anti-inflammatory therapy 3
Worsening symptoms warrant repeat imaging to assess for abscess formation 4
Common Pitfalls to Avoid
Failing to exclude malignancy: Always maintain high suspicion for breast cancer in older men with atypical presentations 5
Unnecessary imaging in clear cases: Can lead to additional unnecessary benign biopsies 5
Overly aggressive initial treatment: Tissue trauma from aggressive interventions may worsen inflammatory mastitis 4
Delayed tissue diagnosis: Understanding the specific pathogenesis through biopsy leads to more targeted and less invasive treatment 1