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.