Objective: Primary nodal and extranodal diffuse large B-cell lymphoma (DLBCL) were investigated for the heterogeneity of histopathology and immunophenotype, and their relation to clinical stage, comparatively. Whether E2F1 can be used as a germinal center B cell (GCB) DLBCL marker was also discussed.
Methods: Classification of histopathology and immunophenotype of 98 cases were studied by immunohistochemistry in tissue microarray.
Results: Histopathologic morphology presented as: centroblastic (CB,88.8%, 87/98), immunoblastic (IB,5.1%, 5/98), anaplastic (ALCL,3.1%, 3/98), and T cell rich B cell lymphoma (TCRBCL,3.1%, 3/98). Of which, 31 cases were GCB DLBCL, 10 (20.8%, 10/48) nodal, and 21 extranodal (42%, 21/50, P=0.024). The rates of Stages I/II in nodal and extranodal area were 48.5% and 70%, respectively (P=0.015). The rate of Stage I/ II in GCB DLBCL (74.2%) were higher than in non-GCB DLBCL (50.7%, P=0.029). The CD10 positive rates were 36.8% and 17.1% in Stages I/II and III/IV, respectively, and had significant differences (P=0.033). The CD10 positive rates were 18.8% and 38% in nodal and extranodal area, respectively (P=0.035). The positive rates of E2F1 were 38.8% and 16.5% in GCB and non-GCB DLBCL, respectively, and had significant differences (P=0.016). The positive rate of E2F1 had positive relation with the expression of CD10 and Bcl-6 (P<0.05).
Conclusion: CB is the most type in 98 cases of DLBCL. The rate of GCB DLBCL was significant higher in extranodal than in nodal areas CD 10 can be used as a prognostic marker. The prognosis of GCB DLBCL is better than that of non-GCB DLBCL. The positive expression of E2F1 can be used as a marker of GCB DLBCL.