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

Abstract

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. 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). 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%). 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.