Immunophenotypic Characterization Of Nonhodgkin Lymphoma

ABSTRACT Background: Non-Hodgkin lymphomas (NHLs) are a heterogeneous group of clonal lymphoid tumours originating from lymphocytes. They constitute about 90% of an estimated 3-4% worldwide distribution of malignant lymphomas among various cancers. It is the commonest haematological malignancy and fifth most common cancer worldwide. Despite the continuous rise and associated deaths, research on non-Hodgkin lymphomas, and in particular the area of immunophenotypic spectrum is limited in Ghana. The situation is not different from other African countries. Identification of NHL-associated immunophenotype plays an essential role towards patient management. Aim: To determine the antigen expressions in non-Hodgkin lymphomas by immunohistochemistry and the identification of the distribution of cell and subtypes. Methods: This is a retrospective, descriptive study in which archived formalin-fixed paraffinembedded tissue blocks of morphologically diagnosed NHLs were used. Clinical and laboratory information of participants were retrieved from the medical records of the Haematology Department, Korle Bu Teaching Hospital. Antigenic phenotypes were determined by immunohistochemistry. Results: A total of 66 cases of NHLs were selected for the study. Mean age of the study was 50.2±16.1 with a range of 16 to 78 years. Males outnumbered females with ratio of 1.54:1. Among the targeted markers, CD20 was the most commonly expressed in 89.4% (59) cases. Immunohistochemistry studies revealed greater proportion of B cell lymphomas of 89.4%. Five subtypes were successfully identified of which diffuse large B cell lymphoma constitutes the predominant group (40.9%). There was 100% agreement between diagnosis made by morpholog and immunophenotype by cell type (P=0.001). Of the clinical characteristics, B-symptoms were the most common feature presented in the study with 87.9% (58) whereas hepatomegaly was the least expressed, 7.6% (5). However, there was no significant association between obvious clinical manifestations and pathological cell types. A substantial amount of B cell 37.3% (22) and T cell 14.7% (1) lymphomas attained clinical remission. A significant association was observed between phenotypic cell types and outcomes of NHLs (p=0.011). Conclusion: Adult Non-Hodgkin lymphomas were mostly due to the malignant transformation of B cell lineage with diffuse large B cell lymphoma being the commonest subtype. Majority of B and T cell lymphomas occurred in males. A significant association was observed between phenotypic cell types and morphology (P=0.001) as well as outcomes of NHLs. The present study therefore serves as a preliminary data for further research towards the adoption of an improved treatment regimen and management of non-Hodgkin lymphomas in Ghana