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Updated: May 17, 2026

RNAscope for In situ Detection of Transcriptionally Active Human Papillomavirus in Head and Neck Squamous Cell Carcinoma
Published on: March 11, 2014
p16 expression in cutaneous squamous carcinomas with neck metastases: a potential pitfall in identifying unknown
Beth M Beadle1, William N William, Michael S McLemore
1Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Background:
Human papillomavirus (HPV) positivity (+) has been used to identify oropharyngeal squamous carcinomas (SCCs) presenting as unknown primaries in the neck. p16 overexpression correlates with HPV+ in the oropharynx; however, the use of p16 alone as a surrogate marker of oropharyngeal HPV+ tumors has not been validated.
Methods:
We immunohistochemically analyzed p16 expression in surgically resected aggressive cutaneous head and neck SCC primaries and their nodal metastases from 24 patients to determine the potential overlap of p16 expression outside of the oropharynx.
Results:
Five of 24 primary tumors (20.8%) and 3 lymph node metastases (12.5%) in levels II, III, and V, and the periparotid region diffusely expressed p16. HPV (high-risk types by in situ hybridization) was negative.
Conclusions:
p16 expression is relatively common in lymph node-positive cutaneous head and neck SCCs; thus, p16 expression as an independent biomarker and mechanism to determine the oropharyngeal source of an unknown primary is not advised.

