Cystic Neutrophilic Granulomatous Mastitis Regression with the Tumor Necrosis Factor-α Inhibitor, Adalimumab.

Idiopathic granulomatous mastitis (IGM) is a rare, benign, inflammatory breast disease that primarily affects parous women within a period of five years post-partum. Cystic neutrophilic granulomatous mastitis (CNGM) is clinically identical to IGM, but histopathology demonstrates distinct central lipid vacuoles rimmed by neutrophils with an outer cuff of epithelioid histiocytes/granulomas, with inconsistent presence of Coryneform bacteria within the vacuoles. There is no consensus on the treatment for either IGM or CNGM, which may be managed surgically with wide local excision or mastectomy or medically with antibiotics, steroids, and steroid-sparing immunosuppressive agents. We present a 30-year-old woman with plaque psoriasis and CNGM whose breast symptoms resolved after treatment with the tumor necrosis factor alpha (TNF-α) inhibitor adalimumab, which has not previously been described as a treatment option for CNGM.