MOLECULAR CHARACTERIZATION OF WARTHIN TUMOR

Objective. Warthin tumor of the salivary gland is composed of oncocyti c epithelium with a prominent follicular lymphoid infiltrate. The purp ose of this study was to characterize the clonality of this lymphoid c omponent by means of polymerase chain reaction technology. Study desig n. DNA was isolated from paraffin-embedded tissue from 20 cases of typ ical Warthin tumor of the salivary gland and amplified by polymerase c hain reaction to assess B-and T-cell clonality. Results. No dominant c lonal populations were identified in any tumor. However, minor clonal expansions of both B and T cells were detected in up to 50% of tumors (immunoglobulin H, 50%; T-cell antigen receptor beta, 10%; T-cell anti gen receptor gamma, 5%). No tumors showed evidence of bcl-2 proto-onco gene translocation, whereas 95% contained detectable Epstein-Barr viru s DNA. Conclusion. The B- and T-cell components of Warthin tumor are p olyclonal with oligoclonal expansion of both T and B cells in some les ions.