Posttransplant Epstein-Barr virus-associated myogenic tumors involving bone - A case report

BACKGROUND. Epstein-Barr virus (EBV)-associated myogenic tumors in immunoco mpromised patients were recently recognized, but their biologic behavior re mains only partially understood. Although observations so far have permitte d the recognition of similarities between posttransplant myogenic tumors an d posttransplant lymphoproliferative disorders (PTLD), the number of report s are still few, and new experiences continue to be informative. METHODS. The authors describe what they believe is the first example of pos ttransplant EBV-associated myogenic tumor involving bone, which is also rem arkable for its multicentric symmetric limb distribution. Immunohistochemis try of tumor cells for myogenic antigens (desmin and smooth muscle actin), EBV antigens (latency proteins latent membrane protein-1 [LMP-1], Epstein-B arr nuclear antigen-2 [EBNA-2], and ZEBRA), p53, and bcl-2 was examined by standard avidin-biotin-peroxidase complex methods. Molecular techniques inv estigated in situ hybridization for Epstein-Barr virus-encoded messenger RN As (EBERs) and single-strand conformation polymorphism analysis for p53 mut ation. RESULTS. Although the biologic behavior of this tumor was uncertain, the re duction of immunosuppression arrested tumor growth for 5 years, at the expe nse some loss in renal function. The occurrence of episodes of acute cellul ar rejection required pulse therapy, resulting in the appearance of new les ions in both liver and lungs. Despite these complications, a balance betwee n control of this multicentric tumor growth and allograft survival has been maintained for 8 years. CONCLUSIONS. To the authors' knowledge, this example of posttransplant myog enic tumor is the first described in the bone. It shows partial response to immunomodulation with persistent tumor, with prolonged survival of the ren al allograft. (C) 2000 American Cancer Society.