Seminar on Idiopathic Granulomatous Mastitis (IGM)

Introduction

Speaker: Initial speaker and multiple experts.
Seminar Title: Focus Studies in Breast Cancer.
Specific Topic: Idiopathic Granulomatous Mastitis (IGM).
Context: IGM can mimic inflammatory diseases and cancer; it poses diagnostic and treatment challenges.

31st seminar conducted every 4-8 weeks for 3 years on breast cancer-related topics.
This seminar witnessed a high number of registrations.
Acknowledged the hard work of younger colleagues.

Topic Selection: Significant deliberation due to the challenging diagnosis and treatment of IGM, which mimics malignancy.
Lecture Coverage: Clinical presentation, diagnostic workup, difficulties, and therapeutic options for IGM.
No specific treatment guidelines exist for IGM.

First Described: Kessler and Wolloch, 1972.
Historically Misdiagnosed: Often mistaken for breast carcinoma, leading to mastectomy.
Initial Paper: Five cases initially thought to be malignant.

Benign Condition: Characterized by granulomas in mammary lobules without identifiable etiological factors.
Proposed Causes: Autoimmune reaction, trauma, metabolic disorders, hormonal imbalance, or infection (e.g., Corynebacterium species).
Precipitating Factors: Pregnancy, lactation, contraceptive use, trauma, smoking, autoimmune disorders, etc.

Common Demographics: Young women, typically 3rd-4th decades, postpartum or lactating women, nonwhite ethnicities (Asians, Hispanics, Middle Eastern women). Rare in males and older women.
Symptoms and Signs:
- Palpable tender mass (sometimes bilateral).
- Nipple discharge, erythema, skin edema, peau d'orange, and occasionally discharging sinuses.
- Axillary lymphadenopathy in 30% cases, usually reactive.

Differential Diagnosis: Includes bacterial abscess, tubercular abscess, fungal infections, foreign body reactions, and malignancy.
Imaging Techniques:
- Ultrasound: Initial imaging modality; might show irregular masses with angular margins.
- Mamography: Can show architectural distortion but not pathognomonic features.
- MRI: Useful for non-conclusive cases, can show heterogeneously enhancing masses and detailed involvement.
Histopathology:
- Core needle biopsy is the gold standard.
- Pathognomonic lobulo-centric granulomas with multinucleated giant cells and microabscesses.
- Key feature: Non-caseating granulomas without infectious causes.

Observation: For mild cases, with periodic follow-up and symptomatic treatment.
Antibiotics: Long-term antibiotics (e.g., Clarithromycin, Doxycycline) in the absence of bacterial culture growth.
Steroids:
- Oral Prednisolone (30-40 mg/day) for 3-6 months and gradual tapering.
- Intralesional and topical steroids as alternatives to reduce systemic side effects.
Immunosuppressants: For steroid-resistant cases, including Methotrexate and others.
Surgery:
- Reserved for non-responsive, severe, or recurrent cases or significant abscess formation.
- Options include surgical debridement, wide local excision, or mastectomy in rare extreme cases.

Multidisciplinary Approach: Involving surgeons, pathologists, radiologists, and occasionally rheumatologists for autoimmune aspects.
Regular Monitoring: With ultrasound to monitor response to treatment.
Patient Counseling: Emphasizing extended treatment durations and managing expectations about recurrence potential.

Common Presentations: Tender masses, abscesses, discharging sinuses.
Initial Investigations: Ultrasound followed by core biopsy; sometimes FNAC for lymph nodes.
Pathology Pitfalls: Importance of experienced pathologists to differentiate from other chronic mastitis forms.
Treatment Approaches:
- Steroid therapy often coupled with antibiotics initially.
- Role of immunosuppressants discussed for resistant cases.
- Surgery as a last resort or for significant complications.

Medications: Prolonged steroids with careful monitoring and tapering methodologies; topical and intralesional options preferred for smaller lesions.
Surgical Interventions: Non-closure for larger lesions, with packing and delayed secondary healing advised by some panelists.
Immunosuppressants Role: Rheumatologist consultations can significantly aid in managing chronic/recurring cases through targeted immunotherapy.

Natural Course: Long-term monitoring needed with the understanding that recurrences and protracted courses are common.
Recommended Practice: Combining various modalities tailored to individual patient responses should be the strategy while emphasizing multidisciplinary collaboration for managing IGM effectively.