Transformation in lymphomas--morphological, immunophenotypic and molecular features

Area of Science:

• Hematology
• Oncology
• Pathology

Background:

• Lymphoma transformation is a clinically aggressive progression of existing lymphoma.
• The clonal relationship and pathogenic mechanisms of transformation remain debated.
• Understanding transformation is crucial for patient management and treatment strategies.

Purpose of the Study:

• To investigate the morphology, immunophenotype (including EBV status), and clonal relationship in lymphoma transformation.
• To analyze nine cases exhibiting lymphoma transformation.
• To elucidate the nature of secondary neoplasms arising during lymphoma progression.

Main Methods:

• Morphological and immunophenotypic analysis of lymphoma tissues.
• Immunohistochemistry for Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1).
• Molecular studies including immunoglobulin gene rearrangement analysis.

Main Results:

• Observed transformations from low-grade B-cell lymphomas to high-grade B-cell lymphomas or Hodgkin lymphoma.
• Documented transformations from Hodgkin lymphoma to diffuse large B-cell lymphoma or peripheral T-cell lymphoma.
• Detected EBV-LMP1 in transformed cells in five cases.
• Identified distinct immunoglobulin gene rearrangement patterns in two cases, indicating de novo origin.

Conclusions:

• Lymphoma transformation is characterized by abrupt clinical, morphological, and phenotypic changes.
• Some instances of lymphoma transformation may represent secondary, de novo neoplasms rather than direct clonal evolution.
• EBV infection may play a role in a subset of lymphoma transformations.