Detection of Epstein-Barr viral genome in tumor cells of Warthin's tumor of parotid gland.

The presence of Epstein-Barr virus (EBV) DNA-sequences in specimens of Warthin's tumor in the parotid gland was studied. Using an in situ hybridization technique, EBV genome was detected in distinct cell types in routinely processed tissues. The authors' results indicated that EBV is frequently present in the cytoplasm (possibly because of a chronic, productive infection) of neoplastic cells of multiple/bilateral Warthin's tumor (MBWT) (86.7%), and only occasionally of solitary Warthin's tumor (SWT) (16.7%). In addition, EBV genome has often been documented in the cytoplasm of ductal cells (75% of MBWT and 33.3% of SWT), and occasionally of acinar cells (16.7% of both MBWT and SWT) of residual normal salivary gland tissue surrounding both MBWT and SWT. The almost constant presence of EBV DNA in tumor cells of MBWT, as opposed to the occasional finding in SWT, suggested a strong association between infection of cells with this virus and the development of multiple/bilateral lesions. The positivity of ductal epithelium supported speculations about the role of ductal cells as a histogenetic precursor of the tumor. This was the first report on the detection of EBV genome in Warthin's tumor.