Primary breast lymphoma is a rare form of non-Hodgkin lymphoma with some distinct clinical features. The most common histopathological type is diffuse large B-cell lymphoma (DLBCL), but other less frequent subtypes are also encountered. In this review, we describe the characteristics of primary breast DLBCL, with emphasis on pathogenesis, staging, risk stratification and prognosis. In addition, key issues regarding therapy and various available therapeutic modalities are addressed, as well as the role of rituximab in therapy and whether central nervous system prophylaxis is still routinely required. There are very few prospective clinical studies addressing therapy, and available data rely mostly on retrospective case series involving small numbers of patients. Our conclusions and proposed recommendations are therefore not offered as formal guidelines. This review attempts to represent an unbiased analysis of the published data and is intended as a useful aid for clinicians treating this uncommon type of extra nodal lymphoma.