Breast lymphomas: a clinicopathologic review.

Primary lymphoma is an uncommon tumor in the breast. Review of the literature shows two distinct clinicopathologic groups. One, which affects young women, is frequently bilateral, is often associated with pregnancy, and is a Burkitt-type lymphoma. The second group affects older women, is usually B-cell non-Hodgkins-type lymphoma, and presents clinical features identical to carcinoma of the breast. Three recent studies have suggested that up to half of the cases in the latter group belong to the category of lymphomas arising from the mucosa-associated lymphoid tissues. We have identified nine cases of primary lymphoma from the files of Guys Hospital Clinical Oncology Breast Unit in the 16-year period from 1974 to 1990. The clinical features have been reviewed and the tumors have been evaluated both on a morphologic and an immunohistochemical basis, and seven of nine of the cases have been screened for t[14;18] translocation using the polymerase chain reaction. All the tumors occurred in women older than 50 years and who presented with features of mammary carcinoma. One tumor was true histiocytic lymphoma; the remaining eight cases were B-cell lymphomas. Seven of the latter cases were high-grade B-cell lymphomas and one was a true follicular lymphoma. None of our cases showed the features of lymphoma arising in mucosa-associated lymphoid tissue.