Epstein-Barr virus-positive diffuse large B-cell lymphomas of the elderly

Area of Science:

• Hematology
• Oncology
• Virology

Background:

• Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) of the elderly is a provisional entity in the 2008 WHO classification.
• It is defined as a blastic, clonal B-cell proliferation associated with EBV in patients over 50, potentially linked to immune senescence.

Purpose of the Study:

• To describe the characteristics, diagnosis, and clinical features of EBV-positive DLBCL of the elderly.
• To differentiate it from other lymphoid malignancies, particularly EBV-positive classical Hodgkin lymphoma.

Main Methods:

• Morphological analysis including polymorphic and monomorphic subtypes.
• Immunohistochemistry for pan-B cell markers, CD30, OCT2, and BOB.1.
• Epstein Barr early RNA in situ hybridization for EBV detection.
• Expression analysis of LMP1 and EBNA2.

Main Results:

• Morphology includes polymorphic or monomorphic subtypes with "geographical" necrosis.
• Tumor cells are positive for pan-B cell markers and often CD30; EBV is present in most tumor cells.
• Expression of LMP1 is common, while EBNA2 indicates immune system impairment.
• Distinguishing features from Hodgkin lymphoma include homogeneous B-cell marker expression and lack of CD15.
• This lymphoma is more prevalent in Asian populations and associated with B-symptoms, poor performance status, and inferior prognosis compared to EBV-negative DLBCL.

Conclusions:

• EBV-positive DLBCL of the elderly exhibits distinct morphological and immunophenotypic features.
• Accurate diagnosis is crucial, especially differentiating it from EBV-positive classical Hodgkin lymphoma in older adults.
• Its higher incidence in Asia suggests geographic or ethnic predisposition.
• The entity's clinical presentation and poor prognosis highlight the need for further research to determine if it's a distinct entity or a DLBCL variant.