[Case #5. Hematologic malignancies of the breast]

Hematolymphoid tumors of the breast are uncommon. They either represent a secondary site of a known hematological malignancy or a primary disease (sometimes linked to systemic treatment such as chemotherapy for other cancers). The majority of primary breast lymphomas are B-cell lymphomas, with diffuse large B-cell lymphoma being the most prevalent. T-cell lymphomas (potentially associated with certain breast implants), plasmacytomas, and myeloid sarcomas have also been reported. The prognosis and treatment depend on the specific type of hematolymphoid neoplasm. It is crucial to identify the hematolymphoid nature of a breast lesion on biopsy to ensure appropriate management and avoid unnecessary surgeries. This situation is a classic challenge due to its rarity, and the pathologists should consider it when dealing with any malignant breast lesion with a "triple-negative" phenotype.