Immunohistopathological Characterization of Lymphomas and Their Relationship With Epstein-Barr Virus Infection in Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria

Abstract Objectives To do an immunohistochemistry study of the lymphoma cases seen in Ile-Ife, Nigeria, within a 7-year period (2008–2014) and determine the frequency of expression of Epstein-Barr virus (EBV) latent membrane protein (LMP1). Methods Fresh histologic and immunohistochemistry sections were prepared from archived formalin-fixed, paraffin-embedded tissue blocks of lymphoma cases. The following antibodies were appropriately employed: CD15, CD30, CD3, CD20, MIB1, CD5, CD23, BCL2, cyclin D1, and LMP1. The results were presented using appropriate tables and charts. The chi-square test was used to compare discontinuous variables, and P < .05 was considered statistically significant. Results There were a total of 81 cases: 16 Hodgkin lymphomas (HLs) and 65 non-Hodgkin lymphomas (NHLs). The male to female ratio was 1.7:1 for HLs and 1.8:1 for NHLs. The mean age at diagnosis was 32.6 ± 4.0 years for HL and 52.2 ± 2.6 years for NHL. The mixed-cellularity and the nodular-sclerosing classical HL subtypes were the commonest subtypes of HL (37.5% each). Only 18.8% (3/16) of HL cases were positive for EBV-LMP1. Diffuse large B-cell lymphoma (DLBCL) was the largest subtype of NHL (50.8%), followed by small lymphocytic lymphoma (20.0%), marginal zone/lymphoplasmacytic lymphoma (10.8%), and Burkitt lymphoma (BL) (9.2%). Follicular lymphoma (3.1%) and T-cell lymphomas (3.1%) were uncommon. Only 3.1% (2/65) of NHLs were positive for EBV-LMP1. Conclusion NHL predominated over HL, and DLBCL was the largest subtype of NHL. T-cell lymphomas and FL were uncommon. Marked reduction in the frequency of BL seen in this study, compared to previous studies, was attributable to increasing reliance on smears only for its diagnosis in our center. Generally, EBV-LMP1 association was found to be comparatively low among HL and NHL cases, and EBV probably does not play a very significant role in the epidemiology of lymphomas in Ile-Ife, Nigeria. There is a need for further studies to substantiate these findings.