POSTTRANSPLANT T-CELL LYMPHOMA - REPORT OF 3 CASES AND A REVIEW OF THE LITERATURE

Background. Although 14% of the malignant lymphomas after organ transp lantation are reported to be T-cell lymphomas, only a few cases are de scribed in the literature. Methods. The authors presented three new ca ses. They summarized the clinical data and analyzed histologic and imm unochemical findings. The presence of Epstein-Barr virus (EBV) and hum an T-cell lymphoma type 1 (HTLV-1) were investigated. T-cell receptor (TCR) rearrangement was analyzed by Southern blot technique in two cas es. Results. Two of the three lymphomas developed after renal transpla ntation. One was a T-cell lymphoma of pleomorphic medium-sized cell ty pe and the other was a T-cell lymphoblastic lymphoma; the third T-cell lymphoma was an anaplastic large cell (Ki-1 positive) type that devel oped after heart transplantation. No association was established with EBV or HTLV-1. A monoclonal TCR rearrangement was found in the two cas es that were analyzed. A literature search revealed 22 other cases. Ni neteen of the 22 reported cases were peripheral T-cell lymphomas. Almo st all lymphomas presented in extranodal sites. The time between diagn osis and organ transplantation seemed to be influenced by the type of immunosuppressive therapy. In five cases, EBV was detected in the tumo r 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 posttranspl ant 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 proliferatio ns, only a minority of the cases are associated with EBV. Most tumors appear to be monoclonal. Prognosis is generally poor, but tumor presen tation with localized disease might have a somewhat better prognosis.