[Immunophenotypes and prognosis of diffuse large B-cell lymphoma: a study of 500 cases].

Objective: To 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.
Methods: Five 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.
Results: DLBCL-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.
Conclusions: By 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.