The granulomatous mastitis is an inflammatory pseudotumor of the breast of which evolution benign but likely to generate important morphological after-effects among young women. This anatomoclinic entity of dubious etiology until these last years poses a problem of differential diagnosis with other etiologies of granulomatosis and especially with inflammatory carcinoma of the breast. The infectious theory is actually based on solid arguments and mainly explains the physiopathology of this affection.