[Lymphocytic mastitis]

Lymphocytic mastitis is a non infectious inflammatory disease of the breast with lobulocentric lymphocytic infiltrate of variable intensity, collagenous fibrosis and progressive lobular atrophy. The pathogenesis of lymphocytic mastitis is still unknown but some recent reports have suggested an autoimmune origin. We investigated a series of 10 cases by immunohistochemistry and we collected patients' biologic data. The most striking histologic feature was a prominent lobulocentric stromal or intraepithelial lymphocytic infiltrate. Occasionally, the infiltrate was perivascular and nodular along the lobule border. B and T lymphocytes, both demonstrated by immunophenotypic analysis, were shown with a particular pattern of distribution. Pathologists must be aware of this disease in order to recommend immunological investigation.