Richter syndrome in chronic lymphocytic leukemia: updates on biology, clinical features and therapy

Abstract

Richter syndrome (RS) or Richter transformation is the development of secondary aggressive lymphoma in the setting of underlying chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Most frequently CLL transforms into diffuse large B-cell lymphoma (DLBCL) (90%) and rarely (10%) into Hodgkin lymphoma, termed Hodgkin variant of Richter syndrome (HvRS). RS is generally characterized by an aggressive clinical course and poor prognosis. In recent years, major advances have been made in understanding genetic events which relate to the progression of CLL or transformation into RS. Better understanding of the molecular pathways has revealed that RS is not a single homogeneous entity. The majority of cases are clonally related to the original CLL clone, while a minority develop from an unrelated clone. This review summarizes new data relating to the molecular biology and the genetic/epigenetic changes occurring during Richter transformation, and also considers the clinical features and therapy for both DLBCL-RS and Hodgkin variant-RS.

Keywords::

• Richter syndrome
• Richter transformation
• chronic lymphocytic leukemia
• DLBCL
• Hodgkin lymphoma

Acknowledgements

We thank Professor Monika Prochorec-Sobieszek from the Department of Diagnostic Hematology, Institute of Hematology and Transfusion Medicine in Warsaw, Poland, for providing the histopathological figures for this article.

Potential conflict of interest

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