Sclerosing lymphocytic lobulitis of the breast--evidence for an autoimmune pathogenesis.

We describe 13 cases of inflammatory lesion of breast lobules in young and middle-aged women, presenting as breast lumps, with, in five cases, associated breast pain. The patient with the most florid bilateral disease subsequently developed Hashimoto's thyroiditis. This prompted us to consider an autoimmune pathogenesis for all the breast lesions. We confirm a previously documented association of such breast lesions with diabetes mellitus and review the evidence for a possible HLA association. Increased HLA-DR expression by breast epithelial cells was observed in cases available for study. Of the seven patients screened for circulating autoantibodies, three had none, one had smooth muscle antibodies, one parietal cell, one parietal cell and thyroid microsomal, and the seventh had the thyroid autoantibodies expected in Hashimoto's disease. Five of seven patients whose HLA-status was determined were HLA-DR3, 4 or 5 positive, either singly or in combination. Immunophenotypic analysis of the mammary lymphoid infiltrate showed that the majority of infiltrating lymphocytes were B-cells.