Infiltrating ductal carcinoma of the breast associated with primary breast lymphoma

We report on the development of an uncommon association of pathologic processes, where an invasive adenocarcinoma of the breast developed concomitantly with a primary lymphoma arising in the same breast. The patient, a 78 year old female, presented with two palpable breast lesions in her left breast and an additional lesion in the right breast. Core needle biopsies of the lesions revealed both ductal carcinoma and lymphoma existing adjacent to each other in the left breast and a second primary lymphoma in her right breast. The mammogram, which also defined the lesions, illustrated collision tumors of the left breast and a separate pathologic process in the right breast. Excision of the lesions confirmed the two independent lesions on the left side, one an infiltrating ductal carcinoma and the second a large B-cell lymphoma. Biopsy of the right breast also demonstrated existence of a large B-cell lymphoma. Left axillary biopsy using sentinel node technology indicated that there was no evidence of nodal metastasis. The question arose as to possible etiologic factors related to viral transfection at the DNA level, that could cause transformation within the ductal epithelium of the breast with similar transfection of the lymphocytes of an adjacent intramammary node, that led to the development of the simultaneous pathologic processes of ductal carcinoma and B-cell lymphoma, defined on biopsy.