An update on granulomatous mastitis: a rare and complex condition

Granulomatous mastitis is a rare inflammatory condition of the breast affecting women of child-bearing age. The disease is characterised by chronic and relapsing inflammation, resulting in scarring and discharging sinuses. Granulomatous mastitis is considered to be idiopathic and the pathogenesis is poorly understood. An amplified immune response has been proposed as a likely cause and there is evidence linking Corynebacterium to some cases of granulomatous mastitis. The presentation is similar to bacterial mastitis or abscess and antibiotics are commonly commenced empirically. The cornerstone of diagnosis is histopathological evaluation on core biopsy; an index of suspicion based on demographic assessment can avoid delays in diagnosis. Management is difficult and there is no consensus on best treatment. Various treatment regimens are described, with high relapse rates relating to the nature of the condition. Watchful waiting is appropriate for mild presentations and steroids are the mainstay of treatment for more severe cases. This article reviews the emerging evidence on granulomatous mastitis and describes an updated approach to management.