Epstein-Barr Virus-Associated Smooth Muscle Tumor of the Larynx: Report of a Rare Case Mimicking Leiomyosarcoma

摘要: We present a patient (male 54 years) with history of renal transplant who 14 years post transplantation developed symptomatic (stridor) laryngeal Epstein Barr virus (EBV)—associated smooth muscle tumor (EBV-SMT) in the absence concomitant disease elsewhere. Nine years subcutaneous EBV-SMT located on calf. The displayed low-grade nuclear atypia and was infiltrating into surrounding soft tissue, focally ulcerating through overlying epithelium. Histologic features included: neoplastic cells myoid differentiation, component primitive appearing small mesenchymal hyperchromatic nuclei, mitotic activity, intralesional to medium sized blood vessels T-lymphocytes. Both cell components strongly expressed actin h-caldesmon, but not desmin, cytokeratins, CD34 or S-100 protein. There strong positive reaction for EBV-RNA situ hybridization (EBER). No other detected clinical radiological examinations no evidence sites, over 8 months follow-up, till death detected. This case emphasizes importance considering this pathologic entity when solitary actin-expressing tumors are encountered larynx immunocompromised patients.