Lymphocytic mastopathy associated with infiltrating lobular breast carcinoma

A case of lymphocytic mastopathy (LM) and concomitant infiltrating lobular breast carcinoma is described. The inflammatory infiltrate cuffed areas of carcinoma. The LM changes also affected lobules that had not been infiltrated by the carcinoma, although adjacent areas contained both in situ and infiltrating tumour. A minor portion of the inflammation was distributed throughout the ducts. The striking lobulocentricity of the inflammatory infiltrate corresponds to previous reports of LM, and distinguishes this case from the inflammatory response commonly associated with breast carcinomas. It is highly likely that the breast carcinoma induced the LM changes in lobules not yet harbouring tumour.