[A case of breast necrosis].

We describe a case of a tumor-like lesion of the breast of a 45-year-old woman. The initial presentation is a persistent breast abscess after three courses of antibiotics. The association with multiple lung nodules suggests a presumed diagnosis of metastatic carcinoma. Fine needle biopsies of breast and pulmonary nodule reveal necrotic tissue without any evidence of malignancy. Systemic symptoms appear after three weeks of evolution : fever, spread cutaneous ulcers, livedo reticularis, arthralgias. The final diagnosis is made on both mastectomy sample analysis demonstrating necrotizing granulomatous vasculitis and presence of antineutrophil antibodies, thus defining Wegener granulomatosis, which initial involvement on the breast is very atypical.