High-grade T-Cell lymphoma complicating B-cell chronic lymphocytic leukemia: An unusual manifestation of "Richter's Syndrome

Approximately 3% of patients with B-cell chronic lymphocytic leukemia (CLL) develop a high-grade large-cell lymphoma consistent with Richter's Syndrom e. In most cases, these lymphomas are of B-cell origin and are believed to arise by clonal evolution from the CLL cells. We present a case of a patien t with a 10-year history of B-CLL who developed an aggressive large-cell ly mphoma, confirmed by immunophenotype to be of T-cell origin. We suggest tha t in patients with CLL, immunodysregulation can result in the proliferation of T cells, which may mutate and result in the development of a new malign ant clone. Am. J. Hematol, 66:203-206, 2001, (C) 2001 Wiley-Liss, Inc.