De novo CD5-positive and Richter's syndrome-associated diffuse large B cell lymphomas are genotypically distinct.

摘要: Diffuse large B cell lymphomas (DLBLs) represent a heterogeneous collection of aggressive non-Hodgkin's that can arise either de novo or as result transformation from chronic lymphocytic leukemia, small lymphoma, follicular lymphomas, mucosa-associated lymphoid tissue. A percentage DLBLs express the CD5 antigen. The majority these cases have evolved pre-existing low grade lymphoma (Richter's syndrome). However, we identified and characterized nine CD5-positive in which patients did not previous history concomitant evidence tissue-associated suggesting they arose novo. All expressed CD20 monotypic immunoglobulin, all eight examined CD19, CD22 CD43, HLA-DR, two CD11c. None CD3, CD10, CD11b, CD21, CD23 CD30. expression by cells was found to be identical leukemia quantitative polymerase chain reaction analysis mRNA. These exhibited clonal immunoglobulin heavy light gene rearrangements but lacked integration Epstein-Barr virus genome structural alterations bcl-1, bcl-2, c-myc, H-ras, K-ras, N-ras proto-oncogenes p53 tumor suppressor gene. bcl-6 proto-oncogene rearrangement, is involved chromosome band 3q27 aberrations, four (44.4%). This comparable with frequency rearrangement CD5-negative DLBL. In contrast, absent six DLBL associated Richter's syndrome. findings suggest are genotypically similar may pathogenetically distinct