Cytological and cilinicopathological findings of 13 cases of primary breast malignant lymphoma

Objective : We determined the cytohistological features of primary breast malignant lymphoma (PBML). Study Design : We cytologically classified 13 PBML cases based on WHO classification and immunohistologically determined cell features using B-cell markers. Result : Of these, 10 cases (77%) consisted of diffuse large B-cell lymphoma (DLBCL), among which tumor cells in 6 were classified into centroblastic (CB) type, 1 CB/Burkitt (CB/B) type, and 3 mixed cell type (Mixed), and 3 (23%) cases classified as mucosa-associated lymphoid tissue lymphoma (MALT). Immunohistologically, tumor cells of in the 10 with DLBCL were positive for multiple myeloma 1 (MUM1) and 2 coexpressing CD10. 8 cases had nongerminal center B cell phenotype. Four of the 6 CB cases showed strongly MUM1-positive lymphoma cells and all 3 Mixed cases were weakly positive for MUM1. The 5-year survival of the 10 DLBCL cases was 65%, with 2 type CB cases dying of disease. Conclusion : The 13 cases we studied showed 3 cytological types of 10 DLBCL cases and 3 MALT, underscoring the importance of understanding the 4 of PBML features in cytological breast-tumor diagnosis, CB type, CB/Burrkit type, Mixed type and MALT type.