Discussion

PBL is a rare form of diffuse large B-cell lymphoma that is characterized by plasmablastic morphology and an immunophenotype that is indicative of a plasma cell differentiation. It was originally described as presenting almost exclusively within the oropharynx of patients positive for HIV. 3 Although there have been case reports of this type of lymphoma in individuals negative for HIV, it is an extremely rare entity in this context. 4–6 PBL is associated with worse outcomes in patients negative for HIV. 7 The reason for this is not entirely understood, but some have suggested that the ability to employ highly active antiretroviral therapy in HIV-positive individuals increases immune response to the tumor and improves overall survival. 8 Richter's transformation is a well-recognized complication of CLL that is characterized by the development of high-grade non-Hodgkin lymphoma, prolymphocytic leukemia, Hodgkin lymphoma, or acute leukemia. 9 Yet PBL arising from CLL is exceedingly rare and has only been reported in a patient with heavily pretreated CLL. 10 To our knowledge, this is the first report of a PBL arising in a setting of previously untreated CLL in an individual negative for HIV.