Richter's transformation in chronic lymphocytic leukemia.

Richter's transformation, or Richter's syndrome, is an uncommon clinicopathological condition observed in about 5% to 10% of patients with chronic lymphocytic leukemia (CLL). "Richter's transformation" refers to the development of aggressive lymphoma during the course of CLL. Diffuse large B-cell lymphoma occurs in the majority of cases of Richter's transformation. Clinically, patients with Richter's transformation present with an aggressive disease course with rapidly enlarging lymph nodes, hepatosplenomegaly, and elevated serum lactate dehydrogenase levels. Specific risk factors for the development of Richter's transformation in a patient with CLL have yet to be identified; however, TP53 disruption, c-MYCabnormalities, unmutated immunoglobulin heavy chain (IGHV) < 2%, non-del13q cytogenetics, CD38 gene polymorphisms, stereotypy, and VH4-39 gene usage may predispose to Richter's transformation. The prognosis is generally poor, with a median survival of about 10 months. Development of rituximab (Rituxan)-containing intensive chemotherapy regimens and chemo-immunotherapy regimens (eg, R-HyperCVAD [rituximab plus hyperfractionated cyclophosphamide, doxorubicin, vincristine, and dexamethasone] or OFAR [oxaliplatin (Eloxatin), fludarabine, and ara-C]) have improved response rates but have not clearly affected long-term outcomes. Allogeneic stem-cell transplantation may offer a chance for prolonged survival.