RESUMEN
Primary non-Hodgkin's lymphoma of the breast is a rare entity representing 0.04-0.5% of all malignant female breast tumors, less than 1% of all patients with non-Hodgkin lymphoma and approximately 1.7-2.2% of all patients with extranodal non-Hodgkin lymphomas. A 75 years old patient presented with masses in the lateral part of the left breast for 6 weeks. Ultrasound detected 3 masses suggesting fibroadenomas while mammography set the suspicion of breast multicentric carcinoma. Fine needle aspiration cytology of one mass showed low grade lymphoma subsequently confirmed with histopathology which diagnosed extranodal non-Hodgkin lymphoma MALT type CD 20+/CD 79a+/CD 3-/Bcl 2- and index of proliferation Ki 67=30% (stage IE). Primary non-Hodgkin lymphomas of the breast, though rare, should be considered in the differential diagnosis of breast malignancies. At present, a standard treatment doesn't exist yet; low grade lymphomas should be managed with excision biopsy and/or local radiation therapy, while high grade lymphomas should be managed with chemotherapy in association with radiation therapy.
