Concurrent classical Hodgkin lymphoma and plasmablastic lymphoma in a patient with chronic lymphocytic leukemia/small lymphocytic lymphoma treated with fludarabine: a dimorphic presentation of iatrogenic immunodeficiency-associated lymphoproliferative disorder with evidence suggestive of multiclonal transformability of B cells by Epstein-Barr virus.

A small fraction of patients with chronic lymphocytic leukemia/small lymphocytic lymphoma develop Epstein-Barr virus-positive B-cell lymphoproliferative disorders. These Epstein-Barr virus-B-cell lymphoproliferative disorders are thought to be related to immune suppression induced by fludarabine/other chemotherapeutic regimens. As in other immunodeficiency-associated lymphoproliferative disorders, these disorders demonstrate a heterogeneous histological spectrum that ranges from polymorphic to monomorphic to classical Hodgkin lymphoma-like lesions. We report a case of concurrent classical Hodgkin lymphoma and plasmablastic lymphoma in a patient with chronic lymphocytic leukemia/small lymphocytic lymphoma treated with fludarabine. Both classical Hodgkin lymphoma and plasmablastic lymphoma were positive for Epstein-Barr virus-encoded RNA, whereas classical Hodgkin lymphoma was also positive for Epstein-Barr virus- latent membrane protein 1, suggesting a different viral latency. Immunoglobulin gene rearrangement studies demonstrated distinct clones in the plasmablastic lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma. These findings suggest biclonal secondary lymphomas associated with iatrogenic immunodeficiency. Epstein-Barr virus-B-cell lymphoproliferative disorders in the setting of chronic lymphocytic leukemia/small lymphocytic lymphoma, in particular those arising after chemotherapy, should be separated from true Richter's transformation, and be categorized as (iatrogenic) immunodeficiency-associated lymphoproliferative disorder.