OBJECTIVETo study the immunophenotype and overall survival of diffuse large B-cell lymphoma (DLBCL) classified according to the 2008 World Health Organization classification of tumors of hematopoietic and lymphoid tissues.

METHODSFive hundred cases of DLBCL were retrospectively analyzed with histologic review, immunohistochemistry, gene rearrangement study, in situ hybridization and fluorescence in situ hybridization. Follow-up data were collected. The overall survival rates of germinal center B-cell (GCB) and non-germinal center B-cell (non-GCB) subtypes, as well as those of DLBCL, not otherwise specified (NOS) and Epstein-Barr virus (EBV)-positive DLBCL of the elderly, were compared.

RESULTSDLBCL-NOS was the commonest subtype which accounted for 77.2% (386/500) of the cases. EBV-positive DLBCL of the elderly, primary DLBCL of central nervous system, primary mediastinal (thymic) large B-cell lymphoma and T cell/histiocyte-rich large B-cell lymphoma accounted for 9.4% (47/500), 4.4% (22/500), 2.8% (14/500) and 2.6% (13/500), respectively. 68.5% (219/320) of DLBCL-NOS belonged to non-GCB subtype. The percentage of GCB subtype and CD5-positive subtype were 28.4% (91/320) and 3.1% (10/320), respectively. Comparison of the overall survival, GCB and non-GCB immunophenotypic groups have no significant difference (P = 0.93). And the same result in which of the EBV-positive DLBCL of the elderly and DLBCL-NOS group, before and after age matched (P = 0.13 and 0.28, respectively). A double-hit lymphoma was found by FISH detection, which presenting as gray zone lymphoma in morphology.

CONCLUSIONSBy using Hans algorithm, GCB and non-GCB subtypes show no significant difference in overall survival. EBV-positive DLBCL of the elderly and DLBCL-NOS also do not have significant difference in overall survival. Fluorescence in situ hybridization technique is helpful in identification of DLBCL with rare phenotypes.