ABSTRACT
Lymphoepithelioma is a lymphocyte-rich, poorly differentiated, nonkeratinizing carcinoma of the nasopharynx with distinctive clinical, epidemiologic, and etiologic features. Histologically and immunophenotypically identical tumors arising outside the nasopharynx are designated lymphoepitheliomalike carcinomas (LELCs), and have been described in the gastrointestinal tract, lung, salivary glands, thymus, and increasingly in the skin. Despite similarities between LELC and nasopharyngeal lymphoepithelioma, there is growing evidence that they are etiologically distinct. Serologic studies and molecular techniques have consistently demonstrated an etiopathologic association between Epstein-Barr virus (EBV) and lymphoepithelioma and LELC of several locations, including stomach, salivary gland, lung, and thymus. Though histologically similar. lymphoepitheliomalike carcinoma of the skin (LELCS) does not contain EBV DNA by RNA in situ hybridization. Recently, techniques for polymerase chain reaction (PCR) using fixed tissue have been described that to our knowledge have not been applied to LELCS. We studied five cases of LELCS, taking advantage of the higher sensitivity of PCR to evaluate the role, if any, of EBV specifically in the pathogenesis of LELCS.
