Richter syndrome first manifesting as cutaneous B-cell lymphoma clonally distinct from primary B-cell chronic lymphocytic leukaemia

Summary Richter syndrome (RS) is a transformation to high‐grade non‐Hodgkin lymphoma in patients with chronic lymphocytic leukaemia (CLL). RS may develop in lymph nodes or rarely extranodally. Skin localization of RS has been described in only a few cases. We present a 77‐year‐old woman who developed isolated diffuse large B‐cell lymphoma (LBCL) in the skin of the nose without any other symptoms of RS. The LBCL in the skin was clonally distinct from the original bone marrow CLL cells. Moreover, LBCL cells were positive for LMP‐1 segment of Epstein–Barr virus and overexpressed p53 protein. The patient was successfully treated with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) and adjuvant local radiotherapy.