title: Epstein-barr virus-associated smooth muscle tumor of the larynx: report of a rare case mimicking leiomyosarcoma.
abstract: We present a patient (male 54 years) with a history of renal transplant who 14 years post transplantation developed a symptomatic (stridor) laryngeal Epstein Barr virus (EBV)-associated smooth muscle tumor (EBV-SMT) in the absence of concomitant disease elsewhere. Nine years post transplantation the patient developed a subcutaneous EBV-SMT tumor located on the calf. The laryngeal tumor displayed low-grade nuclear atypia and was infiltrating into the surrounding soft tissue, focally ulcerating through the overlying epithelium. Histologic features included: neoplastic cells with myoid differentiation, a component of primitive appearing small mesenchymal cells with hyperchromatic nuclei, mitotic activity, intralesional small to medium sized blood vessels and T-lymphocytes. Both the myoid and small cell mesenchymal components strongly expressed smooth muscle actin and h-caldesmon, but not desmin, cytokeratins, CD34 or S-100 protein. There was strong positive nuclear reaction for EBV-RNA on in situ hybridization (EBER). No other tumor was detected on clinical and radiological examinations and no evidence of tumor in other sites, over 8 months of follow-up, till death was detected. This case emphasizes the importance of considering this pathologic entity when solitary smooth muscle actin-expressing tumors are encountered in the larynx of immunocompromised patients.
authors.affiliation: Department of Pathology, National University Health System, 5 Lower Kent Ridge Road, Singapore 119074, Singapore.
authors.forename: Jingxiang
authors.initials: J
authors.lastname: Huang
authors.forename: Kwok Seng
authors.initials: KS
authors.lastname: Loh
authors.forename: Fredrik
authors.initials: F
authors.lastname: Petersson
mesh_terms: D001706:Biopsy; D003937:Diagnosis, Differential; D020031:Epstein-Barr Virus Infections / Q000150:complications*; D006801:Humans; D016030:Kidney Transplantation; D007822:Laryngeal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000821:virology*; D007830:Larynx / Q000000981:diagnostic imaging / Q000473:pathology; D007890:Leiomyosarcoma / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000000981:diagnostic imaging / Q000473:pathology / Q000821:virology; D014057:Tomography, X-Ray Computed