Primary lymphoma of the breast.

Four cases of lymphoma of the breast are described seen over a period of 2 years amongst 362 cases of breast carcinoma and one of carcinosarcoma. All four were diffuse non-Hodgkin's lymphomas, two of IgM-Kappa secreting follicle centre cell and two of histiocyte origin. Routine histological and enzyme histochemical methods were unhelpful but the application of a panel of antisera for the demonstration of immunoglobulin heavy and light chains, lysozyme, alpha-1-antitrypsin as well as carcinoembryonic antigen and epithelial membrane antigen, enabled a confident diagnosis to be made. Primary lymphoma of the breast may not be a rare disease and the possibility exists that it is misdiagnosed as anaplastic carcinoma as indeed two of these cases were on the initial biopsies. Correct diagnosis is essential so that appropriate treatment may be applied.