title: p16INKa immunocytochemistry in fine-needle aspiration cytology smears of metastatic head and neck squamous cell carcinoma.
abstract: OBJECTIVE
  Patients with head and neck squamous cell carcinoma (HNSCC) may initially present with neck metastases diagnosed by fine-needle aspiration (FNA). In these patients, it is critical to locate the primary site so that targeted therapy can be administered. Nearly a quarter of HNSCC are associated with human papillomavirus (HPV) infection. The great majority of HPV-related primaries originate in the oropharynx. p16INKa (p16) functions as a surrogate marker of HPV infection. We sought to determine if expression of p16 by immunocytochemistry (ICC) in neck metastases could assist in localizing the primary site to the oropharynx.
  
  
  METHODS
  Diagnostic FNA cytology smears of neck metastases from 90 patients with biopsy-proven primary HNSCC were reviewed. Papanicolaou-stained slides were directly subjected to ICC, using p16 antibody.
  
  
  RESULTS
  Twenty-seven (30%) tumors expressed p16 by ICC; 74% of these p16-positive tumors were metastases from oropharynx. There was a significantly higher proportion of p16 expression in patients with primary oropharyngeal carcinoma (47%) versus those whose primary tumor was non-oropharyngeal (15%; p = 0.0013).
  
  
  CONCLUSIONS
  p16 expression in FNA cytology smears of metastatic HNSCC is a useful indicator of oropharyngeal origin and can be used to help localize the primary site in cases where this is not clinically evident.
authors.affiliation: Department of Pathology, Halifax Health Medical Center, Daytona Beach, FL, USA.
authors.forename: Reni
authors.initials: R
authors.lastname: Grimes
authors.forename: Monica T
authors.initials: MT
authors.lastname: Garcia-Buitrago
authors.forename: Merce
authors.initials: M
authors.lastname: Jorda
authors.forename: Parvin
authors.initials: P
authors.lastname: Ganjei-Azar
authors.forename: Annapoorna
authors.initials: A
authors.lastname: Ferrell
authors.forename: Carmen
authors.initials: C
authors.lastname: Gomez-Fernandez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D044963:Biopsy, Fine-Needle; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000556:secondary* / Q000821:virology; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000032:analysis / Q000096:biosynthesis*; D005260:Female; D006258:Head and Neck Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009959:Oropharyngeal Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D030361:Papillomavirus Infections / Q000150:complications / Q000175:diagnosis
chemical_list: D014408:Biomarkers, Tumor; D019941:Cyclin-Dependent Kinase Inhibitor p16