Nonnasopharyngeal lymphoepitheliomas (undifferentiated carcinomas) of the upper aerodigestive tract.

Lymphoepitheliomas are malignant tumors of epithelial origin with various amounts of reactive lymphocytic infiltrate. Although initially described in the nasopharynx (World Health Organization type 3 nasopharyngeal carcinoma), these tumors have been identified in various locations throughout the body. A strong association with Epstein-Barr virus (EBV) infection has been established for the nasopharyngeal type. Outside the nasopharynx, lymphoepitheliomas are exceedingly rare in the upper aerodigestive tract, with only isolated case reports of tumors in the larynx, trachea, and hypopharynx. This article features a rare case of lymphoepithelioma of the pyriform sinus. Furthermore, serologic testing, as well as in situ tumor DNA amplification (using the polymerase chain reaction) and hybridization techniques, demonstrated an association of this lesion with EBV infection. The characteristic histopathologic features common to this disease entity are presented, and the literature is reviewed with regard to lymphoepitheliomas of the upper aerodigestive tract outside the nasopharynx. Association of lymphoepitheliomas with EBV infection will be discussed.