Autoimmune rheumatic diseases associated with granulomatous mastitis

Granulomatous mastitis (GM) is a benign, inflammatory condition of the breast that mainly affects women of reproductive age. Although its pathogenesis remains unknown, previous studies revealed an association between autoimmune rheumatic diseases (ARDs) and GM in a subset of patients implicating immune-mediated mechanisms. The aim of this narrative review was to identify and describe the ARDs associated with GM to shed further light on disease pathogenesis. We conducted a comprehensive literature search of patients presenting with GM and coexisting ARDs using electronic databases. An association between GM and various ARDs has been reported, including sarcoidosis, systematic lupus erythematosus, granulomatosis with polyangiitis, psoriasis/psoriatic arthritis, familial Mediterranean fever, ankylosing spondylitis, Sjogren’s syndrome, rheumatoid arthritis, and erythema nodosum, with the most common being granulomatous mastitis—erythema nodosum–arthritis syndrome (GMENA), granulomatosis with polyangiitis (Wegener’s) and sarcoidosis. In addition, clinical characteristics, diagnostic and therapeutic approaches were recorded. Further research is warranted to better understand the association between GM and ARDs and raise awareness amongst rheumatologists.