Transformation of monoclonal B lymphocytosis to Epstein-Barr virus-positive large B-cell lymphoma with intermediate features between diffuse large B-cell lymphoma and classic Hodgkin lymphoma.

Overview

Transformation of chronic lymphocytic leukemia (CLL) to an aggressive lymphoma, so-called Richter syndrome (RS), usually includes diffuse large B-cell lymphoma (DLBCL) and classic Hodgkin lymphoma (CHL). The transformation can be clonally related to the underlying CLL, and is often Epstein-Barr virus (EBV)-associated. Here we report an 86-year-old female with a newly identified CLL-like monoclonal B-lymphocytosis (MBL) who developed diffuse lymphadenopathy. Biopsy of the left axillary lymph node showed EBV-positive large B-cell lymphoma with morphologic and immunophenotypic features intermediate between DLBCL and CHL, so-called gray zone lymphoma. Comprehensive immunophenotypic, cytogenetics and molecular studies demonstrate a clonal relatedness that suggests a transformation from MBL to EBV+ gray zone lymphoma.