T-cell lymphoma presenting in the breast: a histologic, immunophenotypic and molecular genetic study of four cases.

Primary non-Hodgkin's lymphoma of the breast is uncommon. Most primary breast lymphomas are of B-cell phenotype, with only rare cases showing a T-cell phenotype. In this study, we report the clinicopathologic features of four cases of T-cell lymphoma in the breast. The patients all were female with a mean age of 48 years (range, 13 to 77 years). All cases showed immunoreactivity in paraffin-embedded tissue for T-cell markers CD3, CD45RO, and CD43. beta F1 was positive in three of four cases. The four cases were further subclassified as anaplastic large cell lymphoma (CD30 positive) of T-immunophenotype; natural killer/T-cell lymphoma; peripheral T-cell (CD4 positive), large cell type; and peripheral T-cell (CD8 positive, T-cell intracellular antigen positive), medium cell type. Three of the four cases were monoclonal for T-cell receptor beta and/or T-cell receptor gamma. The one case of natural killer/T-cell lymphoma was negative for monoclonality with both T-cell receptor beta and gamma by molecular diagnostic studies. In all cases, IgH was negative. Follow-up was obtained in three cases. Two patients died within less than 1 year after the diagnosis. The third patient died within 18 months of the diagnosis. Our results suggest an aggressive clinical course for T-cell lymphomas that present in the breast.