Posttransplant T-cell lymphoma. Report of three cases and a review of the literature.

BACKGROUND

Although 14% of the malignant lymphomas after organ transplantation are reported to be T-cell lymphomas, only a few cases are described in the literature.

METHODS

The authors presented three new cases. They summarized the clinical data and analyzed histologic and immunochemical findings. The presence of Epstein-Barr virus (EBV) and human T-cell lymphoma type 1 (HTLV-1) were investigated. T-cell receptor (TCR) rearrangement was analyzed by Southern blot technique in two cases.

RESULTS

Two of the three lymphomas developed after renal transplantation. One was a T-cell lymphoma of pleomorphic medium-sized cell type and the other was a T-cell lymphoblastic lymphoma; the third T-cell lymphoma was an anaplastic large cell (Ki-1 positive) type that developed after heart transplantation. No association was established with EBV or HTLV-1. A monoclonal TCR rearrangement was found in the two cases that were analyzed. A literature search revealed 22 other cases. Nineteen of the 22 reported cases were peripheral T-cell lymphomas. Almost all lymphomas presented in extra-nodal sites. The time between diagnosis and organ transplantation seemed to be influenced by the type of immunosuppressive therapy. In five cases, EBV was detected in the tumor cells. A monoclonal T-cell receptor rearrangement was found in eight cases and a polyclonal proliferation in one case. Response to therapy was variable, but often poor.

CONCLUSIONS

The etiology of posttransplant T-cell lymphomas remains unclear. Similarities with posttransplant B-cell proliferations are the predominant extranodal presentation and the finding that the time of occurrence is influenced by the type of immunosuppression. In contrast with posttransplant B-cell proliferations, only a minority of the cases are associated with EBV. Most tumors appear to be monoclonal. Prognosis is generally poor, but tumor presentation with localized disease might have a somewhat better prognosis.