Richter syndrome: a review of clinical, ocular, neurological and other manifestations.

Richter syndrome describes the development of high-grade non-Hodgkin lymphoma (NHL) or Hodgkin lymphoma in patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Richter transformation occurs in 3.3 to 10.6% of patients with CLL. The large cell lymphoma clone occurs by transformation of the original CLL clone in the majority of patients, and as a separate and independent neoplasm in fewer cases. Richter transformation may be triggered by viral infections, such as Epstein-Barr virus infection, which are common in immunosuppressed patients. Trisomy 12 and chromosome 11 abnormalities, as well as multiple genetic defects, have been described in patients with Richter syndrome. These abnormalities may cause CLL cells to proliferate and, by facilitating the acquisition of new genetic abnormalities, to transform into Richter syndrome cells. Presenting features typically include a rapid clinical deterioration with fever in the absence of infection, progressive lymph node enlargement, and an elevation in serum lactate dehydrogenase. Extranodal Richter syndrome has also been reported to occur in the central nervous system, eye, gastrointestinal system, nose, skin, face, bone and bronchus. The therapeutic options include cytoreductive therapy consisting of chemotherapy and immunotherapy, followed by allogeneic stem cell transplantation as postremission therapy.