Lymphoepithelial carcinoma of the parotid gland: a rare neck lump

A 27-year-old southern Chinese woman presented with a 2-year history of painless left-sided parotid mass with no other symptoms, past medical or family history. Initial fine-needle-aspiration cytology demonstrated lymphoid tissue infiltrated by atypical cells with Epstein-Barr virus encoded RNA (EBER) positivity. This raised the possibility of lymphoma, so a superficial parotidectomy for histological diagnosis was performed. Histopathological analysis demonstrated lympho-fibroadipose tissue infiltrated by tumour typical for lymphoepithelial carcinoma. The neoplastic cells expressed pancytokeratin AE1/AE3 and were EBER positive (Figure 1). There was no identifiable surrounding normal tissue suggesting whether this arose within the gland or an intraparotid lymph node. Given her ethnicity, undifferentiated carcinoma of the nasopharyngeal type (UCNT) with nodal metastases was suspected. An examination-underanaesthesia with nasopharyngeal biopsy to elicit the primary site was performed but no malignancy was evidenced. A MRI scan had shown a multifocal left intraparotid mass. A fluoro-deoxy-glucose, positron emission tomography fused with computed tomography (FDG, PET-CT) scan from the skull base to the upper thighs depicted this mass with small-volume regional nodes (Figure 2). Altogether, there were no features suggesting a mucosal primary. Primary lymphoepithelial carcinoma of the parotid or metastatic UCNT of unknown primary origin was the differential diagnosis.