The Burkitt-like lymphomas: a Southwest Oncology Group study delineating phenotypic, genotypic, and clinical features

The Revised European-American Lymphoma classification gives Burkitt-like ly mphoma (BLL) provisional status, leaving unresolved the differential diagno sis with Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL). T his study compared the biologic features of adult BLL and DLBCL. The phenot ypic distinction between BLL and DLBCL was determined by immunohistochemica l staining of frozen tissue from 13 patients with BLL and 55 patients with DLBCL by using an extensive antibody panel including Ki-67, CD10, CD11a/lym phocyte function-associated antigen 1 alpha (LFA-1 alpha), CD18/LFA-1 beta, CD58/LFA-3, and CD54/intercellular adhesion molecule, CD8 for tumor-infilt rating cytotoxic T cells (T-TILs), CD44 homing receptor, and p53 and Bcl-2 oncogenic proteins. Compared with DLBCL, BLL had a higher proliferative rat e (mean Ki-67, 88% versus 53%), greater expression of CD10 and p53 antigens , and decreased expression of Bcl-2, BLL cases had a consistent absence of one or more cell adhesion molecules (92% versus 27%), low T-TIL numbers, an d absence of CD44 homing receptor (92% versus 14%), The t(8;14) translocati on was identified in 80% of BLL cases, but no patients with BLL had the t(1 4;18) translocation, In a 10-year analysis, median survival of patients wit h BLL was 1.2 years, and that of patients with DLBCL was 2.5 years. Althoug h the proportion of patients cured was similar in the 2 groups, BLL patient s had an increased risk of early death. We conclude that BLL can be recogni zed by its combined morphologic and phenotypic features and that it represe nts a high-grade lymphoma much closer to BL than DLBCL, Retention of the BL L category or inclusion of BLL as a variant of BL is biologically and clini cally more appropriate than absorbing the category of BLL into DLBCL. (C) 2 001 by The American Society of Hematology.