Lymphocytic proliferation results from either monoclonal proliferation of neoplastic lymphoma cells or polyclonal proliferation as a normal immune response . A dysregulated or exaggerated response can destroy tissue and impair organ function. Triggers for the activation of cell-mediated immunity are usually microorganisms, such as Epstein-Barr virus (EBV), or possibly neoplastic cells, as seen in paraneoplastic syndromes . With the advancement of immunosuppressive therapy and molecular diagnostic techniques, iatrogenic lymphoproliferative disorder (LPD) in immunodysregulated patients are beginning to be recognized as an emerging medical problem today. We herein report a case of possibly iatrogenic LPD, which required more than two years from the initial presentation until confirmation of malignancy.