Post-transplant EBV-negative anaplastic large-cell lymphoma with dual rearrangement: a propos of two cases and review of the literature.

BACKGROUND: Post-transplant lymphoproliferative disease (PTLD) is a recognized complication of the immunosuppressive regimens associated with solid organ transplantation. The vast majority of these lesions represent monomorphic B-cell lymphoproliferative disease. Rarely, however, T-cell malignancies may emerge, the commonest being anaplastic large-cell lymphoma (ALCL).

MATERIALS AND METHODS: We describe two patients who developed a post-transplant ALCL several years after transplantation. Comprehensive phenotypic and molecular studies were conducted. The technique of capillary gel electrophoresis was employed.

RESULTS: One patient died of unrelated causes, while the other patient did achieve clinical remission. The neoplastic cell populace was composed of CD4-positive cytotoxic T cells exhibiting CD30 positivity. There were very few B cells. Striking and prominent clonally restricted infiltrates were identified whereby there was both a heavy chain and T-cell beta gene rearrangement. There was no evidence of lytic Epstein-Barr virus (EBV) infection.

CONCLUSION: T-cell-associated PTLD does not appear to be directly attributable to EBV infection. Iatrogenic immune dysregulation may result in excessive T-cell proliferation to various antigenic stimuli, hence resembling other drug-associated cell lymphoproliferative conditions such as angioimmunoblastic lymphadenopathy. The dual rearrangement may have some implications regarding the cell of origin.