Patients with idiopathic granulomatous mastitis accompanied by erythema nodosum

Background Idiopathic granulomatous mastitis (IGM) is a rare, chronic inflammatory disease of the breast. The aetiology is unknown. Erythema nodosum (EN) is a rare skin disease associated with IGM. EN is a disease in which the aetiologic factors include infection, malignancy, autoimmune diseases, and pregnancy. Objective The objective of this study was to evaluate the incidence and coexistence of EN with IGM and the approach to treatment. Methods Patients who were admitted to the General Surgery and Dermatology Department of our hospital and diagnosed with EN and IGM were evaluated. Demographic data, symptoms, examination findings, number of birth, smoking, diagnosis and treatment methods, recurrence, and follow-up periods of the patients were evaluated. Results EN was seen in six of the patients admitted to the clinic for IGM. Four patients with EN had pregnancy and all had arthritis. Two patients were not pregnant. Oral methylprednisolone treatment was started in patients whose IGM diagnosis was verified pathologically. Conclusion IGM may be associated with extramammary symptoms such as EN, arthralgia, and episcleritis. These extramammary findings suggest that IGM may be an autoimmune disease. For this reason, breast examination and history of IGM of the breast should be questioned in female patients admitted to different clinics with EN. This way, delays in the diagnosis and treatment of IGM can be prevented.