PURPOSE: Posttransplant lymphoproliferative diseases (PTLDs) represent a group of potentially lethal lymphoid proliferations that may complicate the course of solid organ transplantation. Although early-onset PTLDs frequently have a favorable outcome, late-onset PTLDs behave more alike aggressive lymphoma. We report a monocentric retrospective study that focused on PTLDs occurring later than 1 year after kidney transplantation (very late–onset PTLDs) to define their incidence, clinical presentation, pathologic features, and outcome. We particularly emphasized the follow-up of patients treated with conventional chemotherapy.

PATIENTS AND METHODS: The medical histories of all patients who developed very late–onset PTLD in our institution were reviewed, and diagnostic biopsy materials were retrospectively studied.

RESULTS: Very late–onset PTLDs were diagnosed in 16 (1.1%) of 1,421 patients. Mean (± SD) time to tumor onset was 103.93 ± 70.88 months. Most tumors were Epstein-Barr virus–related monomorphic large-cell PTLDs of B phenotype. Ten patients received conventional chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone regimen). Two of them died within 2 months, two achieved partial remission, and six achieved definitive complete remission. Overall median survival time was 13 months and rose to 27 months in the treated group. The main cause of mortality was sepsis. None of the treated patients experienced rejection despite withdrawal of immunosuppressive treatment.

CONCLUSION: Despite characteristics of aggressive lymphoma, very late–onset PTLDs after renal transplantation may respond to conventional chemotherapy. However, because a high rate of infectious complications occurred, new therapeutic strategies, such as combinations of anti-CD20 monoclonal antibodies and lower doses of chemotherapy, are warranted.