Successful treatment of polymorphic post-transplant lymphoproliferative disorder after allo-HSCT with reduction of immunosuppression.

Post-transplant lymphoproliferative disorder (PTLD) is a life-threatening complication for recipients of solid organ transplantation (SOT) and allogeneic hematopoietic stem cell transplantation (allo-HSCT). In SOT recipients, who previously have a normal immune system that has been immunosuppressed, reduction of immunosuppression (RI) shows favorable outcome. However, in HSCT recipients, who have been profoundly immunosuppressed and for whom the tempo of immune reconstitution cannot be fast enough to eliminate the lymphoproliferative process, RI is ineffective in most patients. Therefore, cases of tumor regression via RI alone are rare in the setting of HSCT. We present a case of 26-year-old female developing a polymorphic B-cell PTLD 4 months after receiving allo-HSCT for T cell lymphoblastic lymphoma. RI alone led to regression of the nasopharyngeal tumor, and no sign or evidence of graft-versus-host disease (GVHD) after RI was observed. The general condition of this patient was quite well just before we submitted our draft. To our knowledge, this is the first case that tumor of PTLD regressed upon RI alone with a favorable prognosis and without any evidence of GVHD and relapse of PTLD after RI therapy in the setting of HSCT, which justify the possible advantage of RI alone for low-risk patients.