Biological and molecular characterization of a rare case of cutaneous Richter syndrome.

Richter syndrome (RS) is the transformation of chronic lymphocytic leukemia in a high-grade lymphoma usually presenting nodal and bone marrow involvement. Richter syndrome can be localized at extranodal sites including the gastrointestinal tract, lungs, and skin. Cutaneous RS is an extremely rare disease apparently showing a less aggressive course than common presentations. While nodal RS has been extensively investigated in literature, pathogenesis and prognosis of cutaneous RS are still partially unknown, even if a role of Epstein-Barr virus infection and p53 disruption has been suggested. Herein, we characterized the histopathological, immunohistochemical features and cytogenetics and molecular alterations of a case of cutaneous RS developed after 8 years chronic lymphocytic leukemia history. Moreover, we reviewed the literature reports concerning cutaneous RS and made a focus on biological patterns and prognostic implications.