Cutaneous Richter's syndrome, prognosis, and clinical, histological and immunohistological patterns: report of four cases and review of the literature

Abstract

Background: Richter's syndrome (RS) corresponds to the transformation of chronic lymphocytic leukemia (CLL) into high-grade lymphoma. RS can involve extranodal sites including the gastrointestinal tract, lungs and skin. Cutaneous RS is rare, we describe 4 cases with clinical manifestations, histological and immunohistological patterns, and outcome.

Methods: Clinical data were analyzed and all patients' skin biopsy samples stained with HE for the CD20, CD5, CD3 and CD30 antigens. Epstein-Barr-virus (EBV)-encoded early RNA and clonal rearrangements were also analyzed.

Results: The patients' mean age at CLL diagnosis was 57 years (53-62 years), with a male/female sex ratio of 3:1. The transformation to cutaneous RS occurred between 8 and 75 months after initial diagnosis and progressed to a fatal systemic disease in 3 cases, between 24 and 129 months. Cutaneous CLL was associated with earlier transformation in our series and could not be distinguished from RS on clinical grounds alone. All patients had a large-cell infiltrate and clonal rearrangements.

Conclusions: The precise mechanism of RS is unclear, but a role of EBV has been suggested in fludarabine-treated CLL. For all our patients, the diagnosis of transformation was made on the basis of cutaneous localizations and led to intensified CLL treatment.