The diagnostic value of HPV detection in squamous cell carcinoma of cervical lymph node metastasis from an unknown primary site (with report of 6 cases)

Objective To evaluate the diagnostic value of HPV detection in squamous cell carcinoma of the cervical lymph node metastasis from an unknown primary site. Methods Clinical data of 6 patients who were initially diagnosed with squamous cell carcinoma of the cervical lymph node metastasis from an unknown primary site and eventually diagnosed with HPV-related oropharyngeal squamous cell carcinoma were collected, and the process of diagnosis was analyzed. Results Upon the initial admission, all patients were diagnosed with squamous cell carcinoma of the cervical lymph node metastasis with positive p16 expression, positive HPV-16 subtype and negative EBER expression. No obvious primary lesion was found after comprehensive examination. Subsequently, four of them underwent ipsilateral tonsollar blind biopsy (n=2) and ipsilateral tonsillectomy (n=2). All these four patients were pathologically diagnosed with tonsillar squamous cell carcinoma. For the other two cases, MRI detected the thickening complicated with enhancement of ipsilateral wall of oropharynx and tongue root after follow-up for D149 and D545 , respectively. Biopsy confirmed the diagnosis of squamous cell carcinoma of the tonsil and tongue root, respectively. Conclusion For patients with HPV-positive squamous cell carcinoma of the cervical lymph node metastasis from an unknown primary site, the possibility that the primary lesion originates from the oropharyngeal site, especially the tonsil and tongue root, should be highly suspected. Key words: Neoplasm, cervical lymph node metastasis; Human papillomavirus; p16; Oropharyngeal carcinoma