A 29-year-old woman noticed a tender mass in her right breast. The patient was seen by her gynaecologist and was prescribed antibiotics for 10 days for mastitis. Subsequently, she underwent a core biopsy of this mass and the pathology showed granulomatous mastitis. Cultures from the biopsy sample were negative for fungus and tuberculosis. The patient's clinical symptoms initially appeared to improve with antibiotic treatment, but were complicated by the formation of an abscess, which was drained in clinic. The patient was referred to rheumatology in anticipation of steroid or methotrexate therapy, and was placed again on antibiotic treatment to which she responded adequately.