Refractory granulomas of breast: Benign or malignant disease.

Abstract

21 Background: Idiopathic granulomatous mastitis (IGM) is an uncommon benign inflammatory breast disease of unknown etiology that may mimic malignancy, infectious diseases, or autoimmune conditions requiring a diagnosis of exclusion. Because the differential diagnosis includes benign as well as malignant disease, an organized approach to the diagnosis and its symptom management is needed. Treatment may include corticosteroids, immunosuppression, or in severe refractory cases, surgery. Methods: This IRB-approved single tertiary referral center study was performed to better characterize the presentation, risk factors, differential diagnosis, and treatment options for IGM. All patients identified in a pathology database with a biopsy consistent with IGM were studied. Data collected included demographics, duration and quality of symptoms, imaging results, microbiology, pathology, systemic and surgical therapies, and outcomes. Results: Between 2006 and 2014, 16 eligible patients were identified. Patients with a prior history of IGM, cancer, or other granulomatous diseases were excluded. Twelve patients were evaluable, and four patients were excluded due to insufficient records. The mean age was 31.9 years (23 to 54) with 50% of patients black and 25% Hispanic. Pregnancy occurred within 5 years of biopsy in 67% of patients. The most common presenting symptom was mass (83%) with focal pain (75%), and the mean duration of symptoms was 5.1 months (0.5 to 16). All microbial cultures were negative. Following diagnosis, systemic treatment included antibiotics (58%), corticosteroids (25%), and methotrexate (17%). Due to refractory symptoms and toxicity despite steroids and methotrexate, surgical intervention was necessary in 67%. Partial mastectomy was performed in 50% and total mastectomy in 17%, with one patient requesting mastectomy for palliation. Conclusions: Although rare, IGM is difficult to diagnose and manage, and an accurate diagnosis must exclude malignancy and other granulomatous processes. Despite the benign nature of the disease, surgical intervention may be required. Systemic treatment with corticosteroids and methotrexate may decrease the need for surgical intervention.