Sentinel case of Richter transformation from chronic lymphocytic leukaemia/small lymphocytic lymphoma to CD3+ diffuse large B-cell lymphoma.

AIM: To report the first case of a Richter syndrome where small lymphocytic lymphoma (SLL) progressed to a CD3+ diffuse large B-cell lymphoma (DLBCL).

METHODS: Macrodissection of small and large cell lymphomatous components was performed. This was followed by flow cytometric analysis along with molecular B-cell immunoglobulin (heavy and light chains) and T-cell receptor (γ and β chains) gene rearrangement studies to investigate a clonal relationship between the components.

RESULTS: The immunophenotypic profile was similar between small and large cell components of the lymphoma by flow cytometry. Furthermore, shared clonal peaks were observed between both components based on molecular B-cell and T-cell receptor gene rearrangement studies, confirming a clonal relationship.

CONCLUSIONS: Chronic lymphocytic leukaemia/SLL may rarely undergo Richter transformation to a DLBCL demonstrating lineage infidelity. This is a potentially important diagnostic pitfall and such cases should not be confused with a de novo T-cell lymphoma.