Akademik Veri Yönetim Sistemi
MODERN PATHOLOGY, cilt.20, sa.9, ss.995-999, 2007 (SCI-Expanded)
Inflammatory myofibroblastic tumors are uncommon lesions composed of spindled myofibroblasts within a variable background of collagen and inflammatory cells. Although the true nature of these lesions is not fully elucidated, identification of consistent cytogenetic alterations in the anaplastic lymphoma kinase ( ALK) gene suggests that they may be neoplastic. A small number of inflammatory myofibroblastic tumors have been reported to harbor human herpesvirus-8 ( HHV-8), implicating the virus in its pathogenesis. In this study, 20 cases of pulmonary inflammatory myofibroblastic tumor were analyzed for the presence of HHV-8 with immunohistochemical and molecular methods. In all cases, antibodies to the latent nuclear antigen of the virus were applied. Four open reading frames ( ORFs), including ORFs K2, 16, 26, and 72, were targeted utilizing realtime polymerase chain reaction ( PCR). The cohort included 9 men and 11 women with a mean age of 37 years ( range, 1-81). Microscopically, the tumors were composed of cytologically bland spindle cells with myofibroblastic differentiation. On immunohistochemical studies, 20% of cases ( 4/ 20) demonstrated diffuse cytoplasmic positivity with ALK. Immunohistochemical staining for the latent nuclear protein of the virus was negative in all cases ( 0/20). All tumors ( 100%, 20/20) tested with real-time PCR were negative for all four ORFs, whereas 100% ( 10/10) of positive control Kaposi sarcoma cases were positive. Her2 gene expression was present in all ( 20/ 20) inflammatory myofibroblastic tumors confirming the presence of amplifiable deoxyribonucleic acid in the tissue lysate. This study documents the absence of HHV-8 in pulmonary inflammatory myofibroblastic tumors, suggesting that further investigation is required to clarify the pathogenesis of this lesion.