Immunohistochemical Expression of CD10, BCL6 and MUM1 in Differentiating Diffuse Large B Cell Lymphoma Subtypes.

OBJECTIVE: To determine the immunohistochemical expression of CD10, BCL6 and MUM1 in differentiating diffuse large B cell lymphoma subtypes.

STUDY DESIGN: Descriptive, cross-sectional study.

PLACE AND DURATION OF STUDY: Department of Histopathology, Armed Forces Institute of Pathology, Rawalpindi, from November 2014 to May 2015.

METHODOLOGY: Newly diagnosed cases of DLBCLon H&E stain as well as IHC markers, according to WHO blue book 2008, were included in the study. Patients' gender, age and site of lymphoma were noted. DLBCLsubtypes (GCB and activated type or non-GCB) were assessed based on IHC expression of CD10, BCL6 and MUM1 and the results were recorded. The data were analyzed by using computer software program SPSS version 20. Descriptive statistics, frequencies and percentages were calculated.

RESULTS: Out of 96 patients, 79 (82%) were male and 17 (18%) were female. Mean age was 54.66 ±16.73 years. Thirty-six (37.5%) cases showed positivity for CD10 and BCL6 both (GCB type), whereas MUM1 was positive in 60 (62.5%) cases (non-GCB type or activated type). Asignificant statistical association was seen between expression of IHC markers (CD10, BCL6 and MUM1) and DLBCLsubtypes (GCB and non-GCB type, p<0.001).

CONCLUSION: In Pakistani population, the frequency of non-GCB type expressing MUM1 is 62.5%, which is quite high as compared to western countries. It needs to be further explored, because it represents high-risk subsets in which alternative strategies for diagnosis and management should be planned.