title: Human papillomavirus in tonsillar squamous cell carcinomas from Guatemala and Brazil.
abstract: OBJECTIVE
  A subgroup of tonsillar squamous cell carcinoma (SCC) is associated with human papillomavirus (HPV). Nevertheless, the prevalence of HPV seems to be variable in different regions and ethnic groups. There are no reports of HPV in tonsillar carcinomas in Guatemala, and data from Brazil are scarce. The aim of this study is to analyze and compare HPV presence in samples of tonsillar SCC from these countries.
  
  
  METHODS
  This study describes the histologic features, expression of p16 by immunohistochemistry (IHC), and HPV by in situ hybridization (ISH) in 13 Guatemalan and 13 Brazilian patients.
  
  
  RESULTS
  All cases of tonsillar SCC from Guatemala were positive for p16, 92% expressed HPV by ISH, and 75% corresponded to the high-risk genotype 16/18. From the Brazilian patients, only four expressed p16, and all were negative for HPV.
  
  
  CONCLUSIONS
  Cases from Guatemala, which were mostly nonkeratinizing SCC and originated from the crypt/reticular epithelium of the tonsil, had high-risk integrated HPV, whereas in Brazilian cases, which were mostly keratinizing SCC that originated from the surface epithelium, there was no association with HPV.
authors.affiliation: Oral Pathology Section, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Brazil. Electronic address: Ali84rum@hotmail.com.
authors.forename: Alicia Rumayor
authors.initials: AR
authors.lastname: Piña
authors.affiliation: Department of Pathology, Medical Sciences Faculty, University of Campinas (UNICAMP), Campinas, Brazil.
authors.forename: Laísa Simakawa
authors.initials: LS
authors.lastname: Jimenez
authors.affiliation: Department of Pathology, Medical Sciences Faculty, University of Campinas (UNICAMP), Campinas, Brazil.
authors.forename: Fernanda Viviane
authors.initials: FV
authors.lastname: Mariano
authors.affiliation: Oral Pathology Section, Department of Oral Diagnosis and Pathology, School of Dentistry, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.
authors.forename: Bruno Augusto Benevenuto
authors.initials: BA
authors.lastname: de Andrade
authors.affiliation: Centro Clínico de Cabeza y Cuello/Hospital Herrera Llerandi, Ciudad de Guatemala, Guatemala.
authors.forename: Román
authors.initials: R
authors.lastname: Carlos
authors.affiliation: Department of Pathology, Medical Sciences Faculty, University of Campinas (UNICAMP), Campinas, Brazil.
authors.forename: Albina
authors.initials: A
authors.lastname: Altemani
authors.affiliation: Oral Pathology Section, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Brazil.
authors.forename: Oslei Paes
authors.initials: OP
authors.lastname: de Almeida
mesh_terms: D000328:Adult; D000368:Aged; D001938:Brazil; D002294:Carcinoma, Squamous Cell / Q000821:virology*; D019941:Cyclin-Dependent Kinase Inhibitor p16; D005260:Female; D006166:Guatemala; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism; D027383:Papillomaviridae / Q000302:isolation & purification*; D012307:Risk Factors; D014067:Tonsillar Neoplasms / Q000821:virology*
chemical_list: C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D009363:Neoplasm Proteins