Evaluation of Immunohistochemical Expression of C-MYC, BCL2, and BCL6 in High Grade B-cell Lymphoma

Background: High-grade B-cell lymphoma (HGBCL) is characterized by chromosomal rearrangements involving specific oncogenes. The most commonly identified oncogenes in B-cell lymphomas are MYC, BCL2, and BCL6. Translocations involving these genes are associated with aggressive tumor behavior and poor clinical outcomes. In these lymphomas, the MYC gene is involved in one rearrangement, while BCL2 and, less commonly, BCL6 participate in additional rearrangements. Objectives: To evaluate the immunohistochemical expression of C-MYC, BCL2, and BCL6 markers in HGBCL cases, as well as to determine the percentage of double-hit and triple-hit lymphoma among HGBCL cases. Materials and methods: Immunohistochemical investigations were conducted for biopsies of 70 selected cases of HGBCL, using the three markers of C-MYC, BCL2, and BCL6. Also, CD20 in conjunction with CD3 was performed for all cases to confirm their B-cell origin. Results: Out of 70 HGBCL patients, C-MYC alteration was expressed in 41% of cases. Eighty-three percent of them expressed BCL2, whereas BCL6 was expressed in 64% of cases. Conversely the double expression of C-MYC/BCL2 was established in 3 cases only (2.1%), while the C-MYC/BCL6 expression was found in 6 cases (4.2%). Most cases of double-hit lymphoma (MYC/BCL2 and MYC/BCL6) occurred in males (67% and 83%, respectively), whereas triple-hit cases were more common in females (61.1%). Conclusion: Regular evaluation of C-MYC, BCL2, and BCL6 expression by immunohistochemistry is fundamental for pathological assessment, risk stratification, and therapeutic planning for affected patients.