Epstein‑Barr virus‑associated lymphoepithelial carcinoma arising in the parotid gland: A case report and literature review

Abstract

A 60-year-old woman presented with a 3-year history of a slow-growing, painless mass in their left parotid gland. Ultrasonography revealed a well-circumscribed, lobulated, hypoechoic mass measuring 19x12x10 mm in the left parotid gland. Computed tomography revealed a well-circumscribed, solid mass with homogeneous enhancement. Fluorodeoxyglucose-positron emission tomography revealed uptake by the tumor but no uptake in other organs, including the nasopharynx. The patient underwent superficial parotidectomy with adequate safety margins and selective neck dissection followed by radiotherapy. No facial paralysis or recurrence of the tumor had been observed as of 20 months post-operation. Histologically, the tumor was composed of sheets of syncytial cancer cells with prominent nucleoli in a dense lymphoplasmacytic background. Epstein-Barr virus (EBV)-encoded RNA in situ hybridization was diffusely positive in the tumor cells. These findings indicated that the tumor was an EBV-associated lymphoepithelial carcinoma. Metastasis, especially from the nasopharynx, was excluded endoscopically and radiologically. Targeted next-generation sequencing of 160 cancer-related genes using the surgical specimen revealed no mutations, including known significant mutations detected in EBV-associated nasopharyngeal carcinoma.

Uncommon Sites of Lymphoepithelial Carcinoma in Head and Neck Region

“…Second FNAC showed negativity to CKAE1/AE3 test. Cytologic features of LEC are large, single and clustered, polygonal and spindle-shaped tumor cells with a high nucleus-to-cytoplasm ratio in syncytial sheets [ 7 ]. Diagnosis of LEC in FNAC is challenging due to its rarity and masking of epithelial elements by a mixed lymphoid population [ 7 ].…”

“…Cytologic features of LEC are large, single and clustered, polygonal and spindle-shaped tumor cells with a high nucleus-to-cytoplasm ratio in syncytial sheets [ 7 ]. Diagnosis of LEC in FNAC is challenging due to its rarity and masking of epithelial elements by a mixed lymphoid population [ 7 ]. Histopathological and immunohistochemical examination, mainly AE1/AE3 which highlight cancer cells, is vital in determining a definite diagnosis in the case of lymphoepithelial carcinoma.…”