Pulmonary Epstein-Barr Virus-Associated Smooth Muscle Tumor after Kidney Transplantation: Two Case Reports with Review of Differential Diagnosis.

Pulmonary nodules are a common complication in solid organ transplant recipients, and may have various underlying causes, with Epstein-Barr virus-associated smooth muscle tumor (EBV-SMT) being one of them. Given the rarity of this entity, we describe the diagnosis and therapeutic interventions for post-transplant EBV-SMT in two individuals. Both cases involved female patients who were diagnosed with multiple pulmonary nodules 60 months and 116 months, respectively, after receiving living-related kidney transplantation. Pathological examination revealed a spindle cell tumor, with immunophenotype and EBV in situ hybridization supporting the diagnosis of EBV-SMT. After diagnosis, these two patients underwent intervention by decreasing their intake of immunosuppressants. As of the latest follow-up, the patients' lesion size remained stable, and their overall condition was favorable. We also reviewed literature about the morphological and molecular pathological features of EBV-SMT and highlighted the diagnosis and differential diagnosis of pulmonary spindle cell lesions especially in the setting of immunosuppression.