Chronic lymphocytic leukemia/small lymphocytic lymphoma with secondary acquisition of t(11;14)(q13;q32)/CCND1-IGH: a rare variant of Richter transformation to mantle cell lymphoma

Abstract Introduction Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) occasionally undergoes Richter transformation, mostly to diffuse large B-cell lymphoma, but its evolution to other types of B-cell lymphoma is rare. We report a CLL evolved to mantle cell lymphoma by acquiring t(11;14)(q13;q32); CCND1-IGH. Method Retrospective review of clinical and laboratory data. Result A 39-year-old male patient was diagnosed with CLL/SLL, and was initially followed without specific treatment, but subsequently received chlorambucil/fludarabine/rituximab due to exacerbated lymphocytosis. While his CLL/SLL waned and waxed, the immunophenotype and genotype of neoplastic B-cells remained unchanged, without cyclin D1 expression and CCND1-IGH fusion. Eleven years after the diagnosis, the patient's disease showed evidence of progression. Bone marrow examination demonstrated "CLL" with the morphology and immunophenotype similar to those seen in the previous biopsies. Unexpectedly, the neoplastic B-cells demonstrated cyclin D1 expression and harbored t(11;14)(q13;q32); CCND1-IGH, suggesting a clonal evolution to mantle cell lymphoma. He subsequently received cytoreductive chemotherapy followed by allogenic bone marrow transplant and remained in remission since then. Conclusion The retention of immunophenotype suggests a clonal relationship between CLL/SLL and mantle cell lymphoma. While the acquisition of t(11;14)(q13;q32); CCND1-IGH likely alters the disease course, the pathogenesis of this illegitimate translocation in CLL remains to be studied.