Granulomatous mastitis, clinical features and treatment

Abstract

Introduction: Idiopathic granulomatous mastitis is a rare inflammatory disease of the mammary gland, occurring in 0.44–1.6% of breast biopsies. The etiology is unknown, although autoimmune processes and subclinical infections have been suggested. The diagnosis is one of exclusion, after ruling out other causes of granulomatous inflammation.

Objective: To determine the clinical characteristics of patients with granulomatous mastitis who consulted at the National Hospital between 2019 and 2025.

Materials and Methods: A descriptive, retrospective, cross-sectional study of patients diagnosed with granulomatous mastitis who consulted at the National Hospital. The diagnosis was made by pathological examination of the breast biopsy. Variables analyzed: sociodemographic variables, number of children, mastitis treatment, and relapse. Results: Twenty-five women were studied, mean age 37 ± 7.2 (21-53). 17 (68%) had primary education, 6 (28.5%) had secondary education, 1 (4.7%) had tertiary education, and 1 (4.7%) had no education. The mean disease duration was 5 ± 3.5 months. The right breast was affected in 12 cases (57%), the left breast in 9 (42.8%), and bilateral breast in 2 (8.2%). All were treated with methotrexate and prednisone. The mean treatment duration was 10 ± 3 months (5-18). Eleven women (45.8%) experienced relapse.

Conclusion: More than half of the patients had a good outcome, with complete regression of the lesion with the combination of methotrexate and prednisone. Almost half of the patients relapsed.