Post-transplant plasmacytoma without Epstein–Barr virus infection occurring rapidly after unrelated allogeneic bone marrow transplantation

Abstract

Post-transplant lymphoproliferative disorders (PTLD) represent a heterogenous group of lymphoid proliferations that develop as a consequence of immunosuppressive therapy in recipients of solid organ or bone marrow (BM) transplantation (BMT). PTLD range from benign hyperplastic lesions to lymphoid neoplasm including plasma cell tumors, and they are mostly Epstein–Barr virus-related [1, 2]. In contrast to the high incidence of post-transplant lymphomas, PTLD manifesting as plasma cell tumors such as multiple myeloma and extranodal plasmacytoma are extremely rare [3]. We report a case of plasmacytoma without evidence of Epstein–Barr virus (EBV) infection which developed rapidly after bone marrow transplantation. A 45-year-old Japanese male with myelodysplastic syndrome (MDS, RAEB-1) received myeloablative allogeneic bone marrow transplantation due to progressive pancytopenia and episodes of recurrent infection. Pretransplant evaluation did not detect plasma cell proliferation in bone marrow aspirate and clot sections, monoclonal gammopathy on serum protein electrophoresis, or splenomegaly on the computed tomography (CT) scan (Fig. 1a). The serum IgG, IgA and IgM values were 1,160, 188, and 123 mg/dl, respectively. These were within the normal range. The conditioning regimen comprised conventional TBI and CY. He had no available HLA-identical family donors. He received an infusion of unmanipulated bone marrow containing 3.6 9 10/kg nucleated cells from a minor ABO-incompatible, one allele-mismatched (HLA DRB1) (disparities in the rejection direction), unrelated male donor. Tacrolimus and short-term MTX were administered for GVHD prophylaxis. Treatment with G-CSF was initiated on day ?5. On day ?7, severe stomatitis and febrile neutropenia (FN) developed. Immediate treatment was started with broad-spectrum antibiotics and an anti-fungal agent. The patient engrafted (ANC[500/mm) on day ?18 after the transplant. However, a platelet count above 5 9 10/mm was not observed. Along with recovery of the neutrophil count, stomatitis and FN improved. Cytomegalovirus (CMV) antigenemia developed on day ?28. Treatment with ganciclovir was started and CMV antigenemia disappeared. The patient did not develop acute graft-versus-host disease (GVHD). On day ?36, a fever of unknown origin and bilateral lower limb pain developed. Radiograph of bilateral lower limb did not show any abnormality including osteolytic lesion. These symptoms did not resolve despite the administration of broad-spectrum antibiotics and an anti-fungal agent. The neutrophil count began to decrease on day ?42. On day ?49, the serum IgG was 1,028 mg/dl, which was within the normal range. K. Kawakami (&) H. Mitani M. Nakao Division of Hematology, Suzuka General Hospital, Yasuzuka-cho, Suzuka, Mie 1275-53, Japan e-mail: Kawakei@cocoa.ocn.ne.jp