ABSTRACT

Background: Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma in the world. It is divided into two important prognostic categories, germinal centre B cell (GCB) and non-germinal centre B cell (non-GCB) subtypes according to the cell of origin. Objectives: In this study, we aimed to determine the frequency of each subtype of DLBCL using a modified Hans algorithm in addition to the association of CD10 and MUM1 immunohistochemical expression with clinicopathological parameters (age, sex, type of specimen (nodal or extranodal) in Ninevah Province (Iraq). Methods: A retrospective and prospective case series study of 61 cases of DLBCL which were collected from histopathological departments of governmental and private labs over 10 months extending from November 2022 to August 2023. DLBCL subtypes (GCB and non-GCB/ABC) were assessed based on immunohistochemical expressions of CD10 and MUM1. Results: A total of 61 patients, (59%) were non-GCB, while (41%) were GCB subtypes. Thirty-four (55.7%) cases were male, whereas twenty-seven (44.3%) were female. The median age was (61 years), 44 (72.1%) cases were nodal and 17 (27.9%) were extranodal primary sites. There is a significant inverse relation between CD10 and MUM1 expression (p-value 0.02). Conclusions: In the Ninevah population, there was a high frequency of unfavourable prognostic markers that included a predominance of non-GCB/ ABC DLBCL. It is necessary to investigate more since it represents high-risk subsets for whom different approaches to diagnosis and treatment should be considered. The significant inverse relation between CD10 and MUM1 supports the Modified Hans algorithm in subtyping DLBCL.