Fine-needle aspiration of cervical lymph nodes yields adequate materials for accurate HPV testing in metastatic head and neck squamous cell carcinomas.

Background: High-risk Human papillomavirus (HR-HPV)-associated head and neck squamous cell carcinoma (HNSCC) is a distinct epidemiologic and pathologic disease. The data of HR-HPV testing on fine-needle aspiration (FNA) materials of cervical lymph nodes in patients with metastatic HNSCC are limited.

Methods: We retrospectively reviewed metastatic HNSCC cases with cervical lymph node FNAs which were tested for p16 immunohistochemistry (IHC) and HR-HPV DNA in situ hybridization (ISH).

Results: Of the 87 cases studied, the overall adequacy rate of cell block material was 86% for HR-HPV ISH, 93% for p16 IHC, 84% for both and 95% for either one. Pathologist-performed FNAs showed significantly higher percentage of satisfactory specimens for p16 and HR-HPV tests than clinician-performed FNAs. Of the 73 cases adequate for both p16 IHC and HR-HPV ISH, the concordant rate between p16 and HR-HPV results was 78%. P16 positivity had sensitivity of 90% and specificity of 75% to predict primary oropharyngeal HNSCC, while HR-HPV test showed a similar high sensitivity (91%) but a better specificity (94%).

Conclusions: FNAs of cervical lymph nodes yield adequate materials for reliable HR-HPV testing in metastatic HNSCCs and should be incorporated into routine pathologic evaluation for these patients. The high concordance between p16 IHC and HR-HPV ISH suggests p16 IHC may serve as a surrogate for HR-HPV ISH in metastatic HNSCC cases with oropharyngeal origin and is helpful to pinpoint primary tumor site. Diagn. Cytopathol. 2016;44:792-798. © 2016 Wiley Periodicals, Inc.