Epstein–Barr Virus‐Associated Smooth Muscle Tumor After Kidney Transplantation: A French Multicenter Retrospective Study

Abstract

BackgroundEpstein–Barr virus (EBV) is a herpesvirus linked to nine different human tumors and lymphoproliferative disorders. Immunosuppression promotes EBV‐driven malignancies. The most frequent EBV‐induced malignancies are lymphomas and nasopharyngeal carcinoma. By promoting smooth muscle proliferation, EBV can induce EBV‐associated smooth muscle tumors (EBV‐SMT). EBV‐SMT is a rare oncological entity for which no current guideline for diagnosis or management exists. Data on posttransplant EBV‐SMT (PT‐SMT) are scarce in kidney transplant recipients.MethodsWe conducted a national multicentric retrospective study and collected cases among transplantation centers in France. Kidney transplant recipients experiencing histologically proven PT‐SMT were included. We collected data on demographic characteristics of patient, history of kidney transplantation, history of PT‐SMT, evolution of graft function, and patient survival.ResultsEight patients were included. The median age at PT‐SMT diagnosis was 31 years (range 6.5–40). PT‐SMT occurred after a median delay of 37.8 months after transplantation (range 6–175). PT‐SMT management consisted in immunosuppressive regimen minimization in all patients. Introduction of mTOR inhibitors was performed in two patients. Four patients (50%) needed chemotherapy. Surgical resection was performed in four patients. At last follow‐up after PT‐SMT diagnosis (median 33 months (range 17–132)), five patients were considered in complete remission, and two patients had died. Two patients experienced graft rejection; two resumed dialysis (25%). All patients with available data presented with impaired graft function at last follow‐up.ConclusionPT‐SMT is a subacute and progressive disease during kidney transplantation. Even if the risk of developing PT‐SMT is low in kidney transplant recipients (0.07% in our cohort), PT‐SMT is associated with significant graft loss, possibly due to reduced immunosuppression. Developing guidelines could help transplantation teams better manage these patients.