A Spectrum of Basaloid Morphology in a Subset of EBV-Associated “Lymphoepithelial Carcinomas” of Major Salivary Glands

Abstract

Nasopharyngeal carcinomas of the undifferentiated or lymphoepithelial type are most commonly seen in South East Asians. Identical tumors have also been described at a variety of other sites including lung, skin and salivary gland and have been referred to by a number of names including lymphoepithelial carcinoma (LEC). LECs of major salivary gland are extremely rare. They are particularly common amongst the Inuit populations of the arctic region including Greenland (Denmark), Canada and Alaska, as well as South East Asians. Within the Inuit group, this tumor represents the majority of all salivary gland carcinomas. Amongst primary LEC of major salivary gland, most cases reported in the literature have represented typical nasopharynx-like tumors. Variants of Epstein-Barr Virus (EBV) associated LEC have not been described previously, to the best of our knowledge. In this report, we describe 4 EBV-associated major salivary gland LECs with prominent basaloid morphology, which represent 22% of a cohort of 18 salivary LECs from an Inuit population in Greenland. The features described in these cases raise a differential diagnosis of other basaloid tumors, particularly in light of the salivary gland location. A basaloid variant of LEC in major salivary gland should be recognized, especially in highly prone populations, to avoid misdiagnosis of other more common salivary tumors.