The Frequency of Double Expresser in Selected Cases of High Grade Diffuse Large B-Cell Lymphomas

Diffuse large B-cell lymphomas (DLBCL) are fast-growing non-Hodgkin lymphomas that affect B-lymphocytes. Double expressor DLBCL is the concomitant expression of Myc and Bcl-2 proteins during lymphomas which results in poor prognosis of patients. This study aimed to determine the frequency of double expresser in high grade diffuse large B-cell lymphomas.

The study was conducted on 74 cases (54 males (68.4%) and 20 females (25.3%)) of DLBCL between August 2018 to January 2019. The mean age of the 74 patients was 51.7 years + 18.5. Expression of proteins c-Myc, Bcl-2 and Bcl-6 were evaluated by immunohistochemistry. The involvement of primary lymph node was reported in 38 cases (51.3%) whereas, extra nodal site was observed in 22 cases (29.7%). Among the primary sites, the cervical lymph node enlargement was the most frequent site of presentation.

The rearrangement pattern was studied among 74 patients, 35 (47%) were found to have either one of the rearrangements i.e. Myc, Bcl-2, or Bcl-6. On the other hand, 14 (18.9%) had shown double rearrangements i.e. Bcl-2 and c-Myc (11 cases) and Bcl-6 and c-Myc (3 cases). The Bcl-2 and Bcl-6 rearrangements were demonstrated by 12 cases whereas 2 cases (2.7%) indicated all three types of rearrangements i.e. c-Myc, Bcl-2, and Bcl-6. In 11 cases the Bcl-2 and c-Myc rearrangements were found to be Bcl-2 > 50% and c-Myc > 40% and demonstrating the overall frequency of double expressers as 14.8%. The prognosis of the mentioned cases was extremely poor, median survival of 10 months.

The concurrent expression of Bcl-2 and c-Myc was found to be 14% (level of expression for Bcl-2 > 50% and c-Myc > 40%) which is potentially a significant health burden and an emerging threat.