EBV⁺ lymphoepithelial carcinoma of the parotid gland in Mexican mestizo patients with chronic autoimmune diseases

Lymphoepithelial carcinomas of the salivary gland are rare tumors constantly associated with Epstein-Barr virus (EBV) and mainly identified in Asiatic and Greenlander population. Four cases have been described in Caucasians, only two with EBV infection. We describe two cases of parotid gland lymphoepithelial carcinomas in Mexican mestizo women in which chronic latent EBV infection was documented by immunohistochemistry and in situ hybridization. One patient had primary Sjögren's syndrome and the other systemic lupus erythematosus of six and three years of evolution, respectively. Epithelial neoplastic cells showed latency pattern II (LMP1⁺, EBNA-2 ^-, EBER⁺) with a dense inflammatory infiltrate composed mainly by CD8⁺ T lymphocytes. Follow-up excluded nasopharyngeal involvement in both patients. This report expands the ethnic groups in which salivary lymphoepithelial carcinomas associated with chronic latent EBV infection have been described, and illustrates for the first time its association with autoimmune diseases in two women living in a region non-endemic for this unusual neoplasm.