Granulomatous mastitis (GM) is a rare benign mammary lesion in which autoimmunity and hyperprolactinemia are considered possible etiological factors. GM has a high frequency of relapse and may lead to chronic ulceration and fistula if not treated properly. Here we report a case of a 22-year-old systemic lupus erythematosus (SLE) patient with three years' disease duration, stable on prednisone and hydroxychloroquine, who was found to have prolactinoma and recurrent GM after she discontinued medication on her own accord. The patient subsequently recovered and remained free of GM relapse under treatment of prednisone, hydroxychloroquine and bromocriptine. Though autoimmune disorders and prolactinoma were reported in GM, a coexisting condition of SLE, prolactinoma, and granulomatous mastitis has rarely been observed in one patient. We suggest our case as an illustrative example of the complex interaction between autoimmunity, neuroendocrine dysfunction, and manifestations in the breast: Immunological disturbances in the background of SLE, coupled with elevated prolactin levels secondary to a prolactinoma, may have predisposed the patient to the development of GM. The mammary lesion recovered and maintained free of relapse under immunosuppressive and antiprolactinemic therapy.
Keywords: Systemic lupus erythematosus; granulomatous mastitis; hyperprolactinemia; prolactinoma.