Postlactational tumoral granulomatous mastitis: a localized immune phenomenon.

Recurrent, nodular necrotizing granulomatous mastitis in two patients is reported in detail. Pathologic, immunologic, and bacteriologic studies in one patient indicate that this entity is different from plasmas cell mastitis, fat necrosis, mammary ductal ectasia, and the usual infectious and puerperal mastitis. Systemic antibreast autoimmune mastitis and vasculitis are also ruled out. Its pathogenesis, differential diagnosis, surgical treatment, and prognosis are discussed.