Epstein-Barr virus-associated smooth muscle tumour in an immunosuppressed patient: a rare clinical scenario

Epstein-Barr virus-associated smooth muscle tumours (EBV-SMTs) are rare neoplasms typically affecting immunosuppressed individuals such as organ transplant recipients. This case follows a woman in her 30s who presented with multi-organ masses 5 years after a kidney transplant. While initial suspicion focused on common post-transplant infections or malignancy, a liver biopsy revealed a smooth muscle neoplasm positive for EBV by EBV-encoded RNA in-situ hybridisation, consistent with EBV-SMT. Managing EBV-SMT is challenging as no standardised treatment regimens exist. When reducing immunosuppression—the conventional first-line approach—failed, a multidisciplinary team opted for a non-standard regimen including Valganciclovir and Pazopanib, which is not a recognised therapy for this condition. The patient achieved a partial metabolic response and maintained stable disease at a 2 year follow-up. This case emphasises the importance of considering this differential when encountering spindle cell neoplasms in an immunosuppressed setting while highlighting the necessity of establishing standardised treatment guidelines for this rare disease.