Background: The incidence of benign and malignant smooth-muscle tumors (leiomyomas and leiomyosarcomas) is increased in children with the acquired immunodeficiency syndrome (AIDS). Epstein-Barr virus (EBV) infection has been implicated in the pathogenesis of these tumors. Smooth muscle tumors in adults with AIDS are extremely rare, with only six cases involving extrapulmonary sites reported in the literature.
Methods: Multifocal smooth walled endobronchial tumors were removed from a 35-year-old man with AIDS using rigid bronchoscopic laser resection. The tumor tissues were processed for routine histology, immunohistochemical stainings, and EBV in situ hybridization using an EBV-encoded RNA- 1 RNA oligonucleotide probe.
Results: Histologic features and immunohistochemical profiles were characteristic of smooth muscle tumors. EBV gene expression was detected in > 90% of tumor cell nuclei. Although overt histopathologic evidence of malignancy was lacking, some of the histopathologic findings, along with multifocality of the tumors and the rapid appearance of new tumors, suggested an unfavorable prognosis in this case.
Conclusions: To the authors' knowledge, this is the first reported case of multicentric smooth muscle tumors involving the bronchi and lungs of an adult patient with AIDS. Diffuse EBV gene expression in the tumor tissue supports the hypothesis that EBV infection contributes to the pathogenesis of tumors of smooth muscle origin in immunocompromised hosts.