Parotid squamous cell carcinoma metastases: Application of human papillomavirus-DNA test on liquid-based cytology to recognize oropharyngeal origin of the neoplasm.

Abstract

Malignancies of the parotid gland are relatively uncommon and in most cases are primary neoplasms; intraparotid metastases are rare. Oral and oropharyngeal squamous cell carcinoma (O- and OP-SCC) can potentially metastasize to the parotid gland or intraparotid lymph nodes. Fine-needle aspiration cytology (FNAC) serves as the initial diagnostic approach for this purpose. HPV status in FNAC specimens is relevant and can guide the diagnostic workup, indicating a potential oropharyngeal origin of the primary tumor. A small series of occult SCC metastases is presented below, in which HPV-DNA testing of FNAC specimens helped identify primary neoplasms located in the oropharynx. US-guided FNAC of parotid nodules was conducted by an experienced interventional cytopathologist in three cases. Each patient underwent assessment of direct smears, cell blocks, and liquid-based samples for HPV testing. The morphological and immunocytochemical features of SCC were documented, and real-time PCR was employed for the detection and genotyping of HPV. The role of HPV testing on FNAC specimens in pinpointing the primary neoplasms in the oropharynx is highlighted. Consequently, FNAC samples emerge as valuable diagnostic and prognostic tools in this context, providing essential insights for patient management.