Epstein-Barr virus-associated smooth muscle tumors after kidney transplantation: treatment and outcomes in a single center

Background Epstein-Barr virus-associated smooth muscle tumors (EBV SMT) in adult kidney transplant recipients (KTR) are rare. The aims of this study are to document the clinical features, types of treatment given, and outcomes of KTR with EBV SMT in our institution. Methods Sixteen patients were identified from our institution's databases. Patients' survival, tumor outcome, and graft survival were compared between patients who remained on cyclosporine-based immunosuppressant and those who converted to sirolimus-based therapy. Results The median time of diagnosis was 9.4yr after kidney transplantation, and majority of the patients had multifocal disease at the time of diagnosis. Overall, the patient survival rate was 75% over a mean follow-up period of fiveyr. Two patients with non-functioning allograft at the time of diagnosis of EBV SMT were excluded from the treatment outcome analysis. Comparing the sirolimus (n=7) vs. cyclosporine groups (n=7), patient survival rate was 100% vs. 42.9% (p=0.08), graft survival 71.4% vs. 28.7% (p=0.53), and disease-free status 42.9% vs. 14.3% (p=0.73), respectively. Conclusion Surgical resection in combination with decreasing immunosuppression or conversion to sirolimus appears to be effective in the treatment of EBV SMT in KTR.