Primary parotid lymphoepithelial carcinoma: A case report and literature review of a rare pathological entity

BACKGROUND: Lymphoepithelial carcinoma (LEC) of the salivary glands is a rare, but distinct, poorly-differentiated neoplasm that resembles undifferentiated nasopharyngeal carcinomas (NPC). Among primary salivary gland LECs, they most commonly arise in the parotid gland. These lesions have a noticeable racial predilection, mostly occurring in Asians and Arctic region native populations. They are strongly associated with Epstein-Barr virus (EBV), and are more common in EBV-endemic areas. The most common presenting symptoms of primary parotid LEC are parotid mass development and cervical lymphadenopathy. We report an unusual case of EBV-negative LEC in a Canadian Caucasian woman. CASE PRESENTATION: A 40-year-old female from Atlantic Canada presented with a rapidly enlarging preauricular mass and cervical lymphadenopathy. Preoperative diagnostics via radiology and fine needle aspiration alluded to an ambiguous primary parotid malignancy. She underwent a total parotidectomy with facial nerve sacrifice and ipsilateral selective neck dissection. The facial nerve was reconstructed with a lateral antecubital nerve graft. Pathology came back positive for LEC, and she began adjuvant radiotherapy. At her 1-year follow up, she was disease-free and obtained a House-Brackmann facial nerve function grade of 3. CONCLUSIONS: The case report highlights the importance of having a high index of suspicion and the need for interdisciplinary collaboration in reaching the diagnosis of primary parotid LEC. LEC can afflict patients of any ethnicity in non-EBV endemic areas and should therefore be considered in all patients with a painless parotid mass regardless of ethnicity. Further studies are required to elucidate the oncogenic role of EBV in these cancers. (C) 2020 The Authors. Published by Elsevier Ltd on behalf of IJS Publishing Group Ltd.