Two Double-hit Lymphomas Cases: A Molecular Cytogenetic Approach

Area of Science:

• Hematology
• Oncology
• Genetics

Background:

• Double-hit lymphomas (DHL) constitute 5% of diffuse large B-cell lymphomas (DLBCL).
• High-grade B-cell lymphomas (HGBCL) with MYC and BCL2/BCL6 rearrangements are defined by the 2016 WHO classification.
• Rearrangements like BCL2 (18q21.33) and MYC (8q24.21) translocations lead to protein overexpression, driving lymphomagenesis.

Purpose of the Study:

• To review the significance of cytogenetic abnormalities in HGBCL.
• To discuss the molecular mechanisms underlying DHL.
• To explore future research avenues in HGBCL and DHL.

Main Methods:

• Review of existing literature on HGBCL cytogenetics.
• Presentation of two patient cases with double-hit lymphomas.
• Description of a molecular cytogenetic approach for detecting MYC, BCL6, and BCL2/IGH rearrangements.

Main Results:

• Translocations such as t(14;18) and t(8;14) are associated with specific lymphoma subtypes.
• Co-occurrence of MYC and BCL2 translocations defines BCL2 and MYC double-hit lymphoma.
• BCL6/MYC DHL are less common and often involve BCL2 as well (triple-hit).

Conclusions:

• Cytogenetic abnormalities are crucial for classifying and understanding HGBCL.
• Accurate detection of gene rearrangements is vital for diagnosis and potential therapeutic strategies.
• Further research is needed to fully elucidate the biology and treatment of DHL.