title: [Immunohistochemical staining of p16 in squamous cell carcinomas of the genital and extragenital area].
abstract: OBJECTIVE
  Positive immunostaining for the tumor suppressor protein p16 is associated with the presence of mucosal or αsubtypes of human papillomavirus (HPV) in cervical and genital squamous cell carcinoma (SCC). The aim of this study was to determine whether p16 immunostaining is also associated with mucosal HPV in extragenital SCC.
  
  
  METHODS
  Paraffin sections of lesions located in the genital region (8 genital warts, 3 intraepidermal SCCs, and 7 invasive SCCs) and extragenital area (29 intraepidermal SCCs corresponding to Bowen disease and 10 invasive SCCs) were stained for p16 by immunohistochemistry. Mucosal HPV was detected by polymerase chain reaction (PCR).
  
  
  RESULTS
  In the genital area, p16 immunostaining was negative in genital warts and positive in all 3 intraepidermal SCCs and 2 invasive SCCs (29%). Mucosal HPV was detected in 6 genital warts and 2 intraepidermal SCCs (100% after exclusion of 3 lesions that could not be analyzed by PCR) and in the 2 invasive SCCs that were positive for p16. In the extragenital area, 19 intraepidermal SCCs (95%) and 2 invasive SCCs (20%) were immunopositive for p16. Mucosal HPV was detected in 4 intraepidermal SCCs (p16 immunopositive) and 1 invasive SCC (p16 immunonegative). In intraepidermal SCCs, p16 immunostaining facilitated the identification of dermal microinfiltration or invasion of normal skin appendages.
  
  
  CONCLUSIONS
  According to our results, unlike in genital SCCs, p16 immunopositivity is independent of the presence of HPV in extragenital SCCs. Compared with intraepidermal SCCs, the absence of p16 protein in invasive SCCs in the extragenital area would indicate progression of the disease.
authors.affiliation: Servicio de Dermatología, Hospital Universitario Virgen de la Arrixaca, Murcia, Spain. raulcorb@gmail.com
authors.forename: R
authors.initials: R
authors.lastname: Corbalán-Vélez
authors.forename: I
authors.initials: I
authors.lastname: Oviedo-Ramírez
authors.forename: J A
authors.initials: JA
authors.lastname: Ruiz-Maciá
authors.forename: P
authors.initials: P
authors.lastname: Conesa-Zamora
authors.forename: M
authors.initials: M
authors.lastname: Sánchez-Hernández
authors.forename: E
authors.initials: E
authors.lastname: Martínez-Barba
authors.forename: C
authors.initials: C
authors.lastname: Brufau-Redondo
authors.forename: J M
authors.initials: JM
authors.lastname: López-Lozano
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000737:chemistry* / Q000473:pathology*; D019941:Cyclin-Dependent Kinase Inhibitor p16; D005260:Female; D005833:Genital Neoplasms, Female / Q000737:chemistry* / Q000473:pathology*; D005834:Genital Neoplasms, Male / Q000737:chemistry* / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009363:Neoplasm Proteins / Q000032:analysis*; D012878:Skin Neoplasms / Q000737:chemistry* / Q000473:pathology*
chemical_list: C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D009363:Neoplasm Proteins