A Case of Bilateral Metachronous Granulomatous Mastitis Leading to Bilateral Total Mastectomy

Abstract

Granulomatous mastitis (GM) is a rare chronic inflammatory disease of the mammary gland, characterized by granuloma or abscess formation, and is often difficult to diagnose and treat. We report a case of bilateral metachronous GM eventually treated by bilateral total mastectomy.

Case : A woman 34-year-old was presented to her doctor with extensive mastitis in her right breast. GM was suspected, but a needle biopsy was not taken to confirm the diagnosis. During the course of disease, the patient developed erythema nodosum. Treatment with pulse steroid therapy resulted in the improvement of the symptoms associated with mastitis. The dose was gradually decreased until the end of the treatment.

Seven months later, she developed mastitis in her left breast. A needle biopsy was taken, and the diagnosis of GM was made. Steroid treatment was initiated, but the symptoms were exacerbated whenever dose reduction was attempted. Although conservative treatment was continued for 7 months, she was referred to our hospital requesting a total bilateral mastectomy.

During bilateral nipple-sparing mastectomy, granulomas in the right breast, which were thought to have been successfully treated, were observed, and bilateral GM was pathologically diagnosed. Her symptoms have not recurred since undergoing surgery.