Breast lymphoma refers to lymphoma that occurs in the breast, while lymphoma is a larger concept that includes lymphomas originating in various lymphoid tissues throughout the body. Lymphoma is a group of malignant tumors originating in lymph nodes and lymphoid tissues, which can involve lymph nodes, liver, spleen, bone marrow and other tissues throughout the body, and can be classified into two major categories of Hodgkin’s lymphoma and non-Hodgkin’s lymphoma according to the pathohistology. In turn, non-Hodgkin’s lymphoma can be divided into precursor lymphoid tumors, mature B-cell origin, mature T and NK cell lymphoma. Breast lymphomas have a low incidence and are overwhelmingly female. Most breast lymphomas are of B-cell origin, and types include diffuse large B-cell lymphoma and lymphoma of the extranodal marginal zone of mucosa-associated lymphoid tissue. It may present as a painless lump in one breast or involve both sides, and is most often accompanied by enlarged lymph nodes. All lymphomas including breast lymphoma need to be diagnosed and typed through a series of examinations in pathology, cytogenetics, and molecular biology, and then appropriate treatment modalities, such as chemotherapy, immunotherapy, and targeted therapy, are selected.