Background: Idiopathic granulomatous lobular mastitis (IGM) is a rare, chronic, inflammatory condition of the breast lobules, primarily affecting women of reproductive age, often within several years after breastfeeding. Although there are many postulated associations and risk factors, the precise etiology remains unknown. Due to the nonspecific nature of symptoms which mimic both infectious mastitis and inflammatory breast cancer, diagnosis is often delayed and the time to complete resolution may be protracted.
Learning Objectives: 1. Patient Demographics and Risk Factors a. Racial and/or Ethnic Predispositions b. Lactation- Extravasated secretions, hyperprolactinemia, pregnancy c. Auto-immune d. Local Trauma- damage to the ductal epithelium 2. Presentation and Imaging on Mammography, Sonography, or Magnetic Resonance Imaging a. Palpable, painful lump i. Mammographic focal asymmetry, developing asymmetry, or mass(es) ii. Sonographic hypoechoic irregular mass(es), micro-abscesses iii. Heterogeneously enhancing MRI masses b. Skin Involvement -skin thickening, fistulas, discoloration of skin c. Diffuse edema with or without adenopathy 3. Pathology a. Necrotizing, noncaseating granulomas centered in the breast lobules b. Exclude infectious mastitis due to mycobacterium, fungal, sarcoidosis 4. Treatment a. Medical treatment i. Antibiotics ii. Steroids-oral or topical iii. Bromocriptine iv. Immunosuppressants b. Radiologic i. Aspiration of abscess(es) ii. Local intralesional steroid injections c. Surgical
Abstract Content/Results: A case series of 35 histopathology proven idiopathic granulomatous cases will be presented in a pictorial essay format. Patient demographics, risk factors, imaging findings, and pathology will be illustrated at presentation and during the course of treatment. Various therapeutic options will be discussed and compared, including medical treatments with antibiotics, steroids (oral and topical) and various immunosuppressants, radiologic interventions with aspirations and intralesional steroid injections, as well as surgical interventions.
Conclusion: The diagnosis and treatment of idiopathic granulomatous mastitis is challenging and requires a multi-disciplinary approach.
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