Lymphoepithelioma-like salivary gland carcinoma in Taiwan: a clinicopathological study of nine cases demonstrating a strong association with Epstein-Barr virus.

Abstract

Lymphoepithelioma-like carcinoma (LELC) of the salivary glands is a rather rare tumour. Previous studies have shown its strong association with Epstein-Barr virus (EBV) among Chinese and Eskimos. We tested this observation with nine Chinese patients with salivary gland LELC in Taiwan including one with coexisting nasopharyngeal carcinoma (NPC) and studied the prognostic significance of their histopathological features. This series showed a predilection for female patients and parotid glands with a median age of 50 years. Three patients died 18.5-26 months after the diagnosis including the case with NPC. Six patients were alive without recurrence for 14-45 months with a median follow-up of 34.5 months. Histopathologically, the tumours showed either lobular or diffuse growth pattern. Granulomas and/or germinal centres were observed in most cases and both B- and T-cells were found in the lymphoid infiltrates, indicating that the salivary gland LELC was capable of inducing a strong host immune reaction. Microscopic growth pattern, lymph node metastasis, and presence or absence of granulomas and/or germinal centres seemed to be important prognostic factors. Both salivary gland LELC and NPC shared similar histopathological appearance and positive immunostaining for epithelial membrane antigen and cytokeratin AE1 but not AE3. Granulomas and amyloid might occur in both tumours. A nasopharyngeal examination is indicated in patients with salivary gland LELC to exclude the possibility of coexisting or metastatic NPC. All nine cases showed positive nuclear signals for EBV-encoded RNA by in situ hybridization including the case with NPC. Our study and the previously published studies show that the association of salivary gland LELC and EBV is strongly related to racial and geographical factors.