ABSTRACT
BACKGROUND: Pleomorphic adenomas and Warthin's tumors are the two most common benign parotid tumors. Previous studies investigating the role of viruses in tumorigenesis of these neoplasms have been conflicting. The aim of this study was to determine whether Epstein-Barr virus (EBV) or cytomegalovirus (CMV) might play a role in the pathogenesis of pleomorphic adenomas and Warthin's tumors. METHODS: Paraffin-embedded surgical specimens of 24 pleomorphic adenomas, 10 Warthin's tumors, and 13 normal parotid tissues were obtained from the University of California-San Francisco Pathology Department. Genomic DNA was extracted from the specimens, and primers for connexin 26, a gap junction protein, were used to confirm the integrity of this DNA. The presence or absence of EBV and CMV DNA within the samples was determined with PCR-based assays, in which radiolabeled primers were used for maximal sensitivity of detection. RESULTS: PCR analysis of serially diluted control DNA revealed that using radiolabeled primers, five copies of viral DNA could be detected. By use of this method, we showed that none of the 24 pleomorphic adenomas, 10 Warthin's tumors, or 13 normal parotid samples contained EBV DNA or CMV DNA. CONCLUSIONS: These results do not support CMV or EBV as etiologic factors in pleomorphic adenomas or Warthin's tumors. In addition, normal parotid seems not to harbor either of these viruses. Future studies with larger numbers of specimens are needed to confirm these findings.
