Objective: To investigate the expression of B cell-specific activator protein (BSAP)/Pax-5 in lymphomas.
Methods: One hundred and two cases of diffuse large B-cell lymphoma (DLBCL), 3 cases of follicular lymphoma (FL), 3 cases of extranodal marginal zone B-cell lymphoma, 1 case of nodular lymphocyte predominant Hodgkin lymphoma (NLPHL), 10 cases of anaplastic large cell lymphoma (ALCL) and 10 cases of plasmacytoma were studied immunohistochemically for BSAP and CD20.
Results: The tumor cells in the 102 cases of DLBCL all expressed CD20, amongst which 100 cases also expressed BSAP. Three cases of FL, 3 cases of extranodal marginal zone B-cell lymphoma and 1 case of NLPHL also expressed BSAP and CD20. All the ALCLs and plasmacytomas did not express BSAP and CD20. The expression rates of CD20 and BSAP were highly consistent. The intensity of staining showed no statistical significance.
Conclusions: BSAP/Pax-5 is a novel B-cell marker expressed in tumor nuclei of B-cell lymphomas. Though less sensitive than CD20, anti-BSAP has diagnostic value in routine surgical pathology practice.