A Proposal of a Clinically Based Classification for Idiopathic Granulomatous Mastitis

Objectives: There is no consensus regarding the surgical or immunosuppressive treatment of idiopathic granulomatous mastitis (IGM). This study aimed to introduce a clinical classification system for IGM that might facilitate its treatment and predict recurrence. Methods: We analyzed the management of 68 patients with IGM at (Princess Basma Teaching Hospital and King Abdulla University Hospital (1994-2016) to find out if distinct patterns of presentation exist according to the following parameters: presence of a painful or painless breast mass, local inflammation, abscess formation, communication to the skin, and extra-mammary manifestation. Results: We identified four distinct patterns of IGM: A: (13.23 %) A hard, painless breast mass. B: (52.94 %) A hard, painful breast mass with gross inflammation. C: (26.47 %) A breast abscess-like presentation. D: (7. 35 %) A subacute presentation with ulceration, sinus, or fistula formation. Erythema nodosum might complicate any of these patterns. Wide local excision in pattern A was curative with zero recurrence rate. The recurrence rates in patterns B and C were 22.20 % and 50.00 %. Patterns B, C, and D were treated by a combination of surgery and prednisolone. In keeping with this, recent literature is in favor of a wider use of immunosuppression especially in the presence of pus and extra-mammary findings. Conclusion: IGM could be classified into 4 distinct patterns according to the presenting signs and symptoms. These patterns correlated with treatment, recurrence rate, and the gross operative findings. This is the first step toward a classification for IGM. Multicenter and Meta-analysis studies are essential for a comprehensive prognostic classification. Treatment of IGM in any institution should be the responsibility of a multidisciplinary team.