Abstract: 0264
Authors: Genta M et al.

zum Abstract

Key content:
In this case series 13 women (median age 39 yrs) with granulomatous mastitis referred to rheumatology practice were described. Idiopathic Granulomatous Mastitis (IGM) is a rare, chronic infammatory breast disease of unknown etiology characterized by non-caseating granulomas in breast tissue, affecting primarily women of child-bearing age. The diagnosis is made by histological examination after excluding other conditions (particularly malignancy and infections). Management options are limited and include observation, antibiotics, corticosteroids, and methotrexate (MTX). Progression and recurrence are common despite treatment.

In the 13 women with IGM biopsy revealed non-necrotizing granulomas and no malignancy; cultures were negative for bacteria, mycobacteria and fungi. All patients were otherwise in good health. ANCA panel, ACE levels, and chest X-ray to gain insights into possible non-caseating granulomatous diseases (e.g., sarcoidosis and ANCA-associated vasculitis) were negative.  Previous treatments by the referring breast surgeons, including antibiotics or anti-fungal only (4 patients), antibiotics and corticosteroids (3 patients), and corticosteroids only (6 patients), had failed to induce improvement. Two patients improved with corticosteroids alone; MTX was used in 6 patients. In 5 patients with persistent or recurrent manifestations (multiple masses, marked drainage, severe pain) anti-TNF-α agents (etanercept or adalimumab) were added. Four of this 5 patients experienced substantial clinical improvement and the lesions resolved completely.

Idiopathic Granulomatous Mastitis (IGM) is a rare, chronic inflammatory breast disease of unknown etiology. The histologic findings of non-necrotizing granulomas implies a similarity to sarcoidosis but as in this case series the disease is limited to the breast. There are no evidence-based guidelines on the management for IGM. Treatments include observation, antibiotics, systemic or intra-lesional corticosteroids, MTX (alone or as steroid sparing), and rarely surgery. Many patients do not tolerate systemic corticosteroids and MTX is maybe contraindicated in child-bearing women. Anti-TNF-α agents may represent a good alternative as shown in this case series with good response in otherwise difficult to treat patients.

Since gynaecologists are not experienced dealing with immunosuppressant drugs, rheumatologists may be the responsible physicians in the future in treating these women and therefore should know the disease.

Dr. Thomas Langenegger