Idiopathic granulomatous mastitis: a heterogeneous disease with variable clinical presentation

Abstract

Introduction: Idiopathic granulomatous mastitis (IGM) is a rare benign inflammatory breast disease that presents with variable local manifestations. We describe here the different management protocols based on the clinical presentation of these patients.

Methods: A retrospective review of 20 histopathologic confirmed cases of IGM seen over a period of 10 years was performed.

Results: The median age was 34 years (age range: 21-45 years). All were married, parous with history of breast feeding. Ill-defined mass mimicking carcinoma was the commonest presentation (70%); however, with the presence of signs of inflammation like pain (55%), redness (40%), and peau d'orange (40%), an inflammatory process appeared more likely. Axillary lymph node enlargement was infrequently seen (40%). Radiologic findings (mammography and ultrasound) were nonspecific. Histopathology showed the characteristic lobular distribution of granulomatous inflammation in all cases. Surgically, 7 patients had abscess drainage with open biopsy, and 7 patients had lumpectomy. Six patients with diffuse breast involvement were diagnosed by core needle biopsy only. Microbial cultures showed no growth. Antibiotics were given empirically when signs of inflammation where present. Two patients needed further abscess drainage followed by persistent sinus excision 3-6 weeks later. The median follow-up was 24 months (range: 15-42 months). Seventeen patients (85%) were recurrence-free, and 3 patients (15%) were lost to follow-up.

Conclusions: Management of IGM cases needs to be tailored according to the clinical presentation. Precise radiologic and pathologic data interpretation by a multidisciplinary breast team will facilitate diagnosis and minimize unnecessary intervention.