Richter's syndrome: Novel and promising therapeutic alternatives.

Richter's syndrome (RS) is the development of an aggressive lymphoma in patients with a previous or concomitant diagnosis of chronic lymphocytic leukemia (CLL). The incidence rate for RS is ∼0.5% per year of observation. In the presence of clinical suspicious of RS, diagnosis of transformation and choice of the site of biopsy may take advantage of 18FDG PET/CT. Molecular lesions of tumor suppression regulators (TP53), cell cycle (CDKN2A) and cell proliferation (NOTCH1, MYC) overall account for ∼90% of RS and may be responsible for its aggressive clinical phenotype. The prognosis of RS is generally highly unfavorable. However, the pattern of survival is not homogeneous and the clonal relationship between the CLL and the aggressive lymphoma clones is the most important prognostic factor. Rituximab-containing polychemotherapy represents the back-bone for induction treatment in RS. Younger patients who respond to induction therapy should be offered stem cell transplant to prolong survival.