Lymphoma in the breast.

Lymphoma is a rare neoplasm in the breast. In this location, it may be primary or secondary, depending on whether there is lymphoma elsewhere in the body. The most common presentation of breast lymphoma is a painless palpable mass, indistinguishable from that of breast carcinoma, although the treatment regimens for these two neoplasms differ vastly. Knowledge of the varied mammographic and sonographic presentations of breast lymphoma should prompt more frequent recognition of this unusual malignant entity. Proper diagnosis of this neoplasm is of the utmost importance to guide appropriate treatment planning and prevent unnecessary and potentially harmful surgery. We describe secondary breast lymphoma in a woman who had been diagnosed and treated for non-Hodgkin's lymphoma several years earlier.