Cutaneous Richter syndrome: report of 3 cases from one institution.

Richter syndrome (RS) is large-cell transformation of chronic lymphocytic leukemia (CLL). It commonly involves lymph nodes and bone marrow, but may rarely manifest in skin. Certain triggering factors, such as Epstein-Barr virus infection and p53 overexpression, have been implicated in the pathogenesis of RS. Here, we present 3 cases of cutaneous RS from our institution with a follow-up period of up to 8 years.We present a series of cutaneous RS from a single institution with the longest follow-up period (up to 8 years) to date.Clinical characteristics were collected and histopathological findings of skin biopsy specimens were analyzed.All 3 patients had prior CLL and later developed cutaneous RS lesions. The mean age at the diagnosis of cutaneous RS was 67 years old. The time intervals between CLL and cutaneous RS were 3 to 8 years. Skin biopsy specimens demonstrated dermal nodular or perivascular infiltrates of large B cells, showing similar immunophenotypes to the lesional cells in the original CLL. Overexpression of p53 and positive stain for Epstein-Barr virus--encoded small RNA was found in one patient. One patient remained alive 8 years after the diagnosis whereas the other two died of the disease at 5 years and 3 weeks, respectively, after the onset of cutaneous RS.Three patients with RS were followed up for up to 8 years.Our findings suggested that, in contrast to extracutaneous RS, cutaneous RS generally has a less aggressive course with longer survival unless other worse prognostic factors are present.