Introduction: Plasmablastic lymphoma, a rare and aggressive form of Non-Hodgkins lymphoma, rarely presents as a retroperitoneal mass. There are no case reports in the literature of plasmablastic lymphoma presenting in living, HIV-negative patient status post liver transplantation.Presentation of Case: We report the case of a 63 year-old HIV-negative male status post liver transplant who presented with weakness and obstructive uropathy. Imaging showed a large mass in the retroperitonium. Biopsy revealed plasmablastic lymphoma. CHOP therapy was initiated and after six cycles, the retroperitoneal mass regressed in size; however, cytology from pleural fluid revealed that the disease remained. It has been 9 months since initial diagnosis and he was started on salvage chemotherapy with ESHAP however he subsequently developed a treatment related myelodysplastic syndrome with trisomy 12.Conclusions: The present case is used to explore the presentation and treatment of plasmablastic lymphoma, and to review the literature concerning the rarity of this disease in the setting of a HIV-negative patient status post solid organ transplantation
