BACKGROUND Idiopathic granulomatous mastitis (IGM) was described as a specific entity in 1972 by Kessler and Wolloch. Despite the 120 cases reported in the international literature, this pathology remains quite unknown. METHODS Four cases of idiopathic granulomatous mastitis are reported in this article in order to outline the main clinical features of this affection. Data in the literature were used to discuss diagnostic and therapeutic particularities. CONCLUSIONS The histologic findings of a non-caseating granulomatous inflammation, centered on breast lobules, composed of epithelioid cells and multinucleated giant cells, allow establishing the diagnosis of granulomatous mastitis (GM). The main presenting symptom of GM is a single inflammatory mass of the breast; the diagnosis is thus often mistaken for breast carcinoma (more than 50% of the reported cases). Radiologic and cytologic findings alone do not enable reaching certain diagnosis because they cannot resolve the differential diagnosis of inflammatory process and malignancy. The diagnosis of IGM can be established after the etiological work up remains negative. A course of oral corticosteroid therapy, non-steroidian anti-inflammatory drugs, or colchicine can be used in order to shrink the breast mass, allowing more conservative surgery. Local excision is of limited benefit as there is a strong tendency for recurrence. CONCLUSIONS Different therapeutic options of IGM are explained by its clinical variability. A more pragmatic therapeutic approach would be enabled by a new classification based on course and severity.