Temporal resolution of idiopathic granulomatous mastitis with resumption of bromocriptine therapy for prolactinoma

INTRODUCTION: Idiopathic granulomatous mastitis (IGM) is becoming more commonly recognized and reported more often. Currently, many recommend corticosteroids in its management. PRESENTATION OF CASE: A 34-year-old G3P2 Hispanic female, 28 weeks pregnant, presented with a 19 cm right breast mass. She had a known prolactinoma treated with bromocriptine which was discontinued during her pregnancy. Ultrasound guided core biopsy procedure revealed granulomatous mastitis. The patient was told that the mass would resolve with observation. The patient seen at another institution by an infectious disease specialist who started treatment with amphotericin for presumptive disseminated coccidioidomycosis. Repeated titers were negative for coccidioides antibody. Repeat cultures were negative as well. Due to the persistence of the infectious disease specialist, tissue cultures were performed on fresh tissue specimens, which did not grow bacterial, fungal, nor acid fast organisms. The amphotericin regimen resulted in no improvement of her breast mass after 10 weeks. Within two weeks of stopping the antifungal therapy, however, the mass diminished to 6 cm. The patient delivered at 39 weeks. Bromocriptine was restarted, and within 4 weeks, the lesion was no longer palpable. She had not shown signs of recurrence for 32 months. DISCUSSION: Treatment recommendations for IGM vary widely but antibiotics and antifungal medications are not recommended. Corticosteroid treatment is most commonly recommended, however, outcomes may not be different from management with observation. Prolactin may be involved in the pathophysiology of the process. CONCLUSION: IGM is becoming recognized more frequently. Observation and patience with natural history can be an effective management.