title: Tissue microarray use for immunohistochemical study of ameloblastoma.
abstract: BACKGROUND
  Ameloblastoma is a locally aggressive odontogenic tumor with high rates of recurrence. To better understand the molecular basis of ameloblastoma, tissue microarray (TMA) may represent a useful tool. However, despite TMA has been considered a high-throughput technique for different human neoplasms, it remains to be validated in the ameloblastoma context. Therefore, the objective of this study was to validate TMA for immunohistochemical study of ameloblastoma, determining its most appropriate design.
  
  
  METHODS
  Forty cases of ameloblastoma were manually distributed in two TMA blocks assembled in triplicate containing 1.0- and 2.0-mm cores (20 cases each). Immunohistochemistry for cytokeratins 14 and 19, and Bcl-2 and Ki-67 was performed, and semiquantitative analysis was performed. Results obtained with TMA sections were compared to their corresponding conventional whole-section slides (CWSS).
  
  
  RESULTS
  Kappa statistical test demonstrated that both 1.0- and 2.0-mm cores assessed as duplicate or triplicate significantly correlated with CWSS, with higher levels obtained using Ki67 (k = 0.98, 0.97, 0.88, 0.87) and CK19 (k = 0.62, 0.58, 0.85, 0.85). There was no significant difference between 1.0- and 2.0-mm cores, and between duplicate and triplicate values. 1.0-mm TMA showed a higher index of core loss (33.74% vs. 4.99%).
  
  
  CONCLUSIONS
  Using a manual arrayer, it was demonstrated that 1.0-mm TMA arranged in duplicate is a valid method for ameloblastoma immunohistochemical study with satisfactory levels of agreement between TMA cylinders and CWSS.
authors: Oral Diagnosis Department, Semiology and Pathology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, São Paulo, Brazil.
authors: Rodrigo
authors: R
authors: Neves-Silva
authors: Oral Diagnosis Department, Semiology and Pathology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, São Paulo, Brazil.
authors: Felipe Paiva
authors: FP
authors: Fonseca
authors: Service of Oral Pathology, João de Barros Barreto University Hospital, Federal University of Pará, Belém, Pará, Brazil.
authors: Adriana Souza
authors: AS
authors: de Jesus
authors: Service of Oral Pathology, João de Barros Barreto University Hospital, Federal University of Pará, Belém, Pará, Brazil.
authors: Hélder Antônio Rebelo
authors: HA
authors: Pontes
authors: Medical School, Clinics Hospital, University of São Paulo, São Paulo, São Paulo, Brazil.
authors: André Caroli
authors: AC
authors: Rocha
authors: Oral Diagnosis Department, Semiology and Pathology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, São Paulo, Brazil.
authors: Thais Bianca
authors: TB
authors: Brandão
authors: Oral Diagnosis Department, Semiology and Pathology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, São Paulo, Brazil.|Department of Oral Pathology and Oral Biology, School of Dentistry, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
authors: Pablo Agustin
authors: PA
authors: Vargas
authors: Oral Diagnosis Department, Semiology and Pathology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, São Paulo, Brazil.
authors: Márcio Ajudarte
authors: MA
authors: Lopes
authors: Oral Diagnosis Department, Semiology and Pathology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, São Paulo, Brazil.
authors: Oslei Paes
authors: OP
authors: de Almeida
authors: Oral Diagnosis Department, Semiology and Pathology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, São Paulo, Brazil. alanroger@fop.unicamp.br.
authors: Alan Roger
authors: AR
authors: Santos-Silva
mesh_terms: D000328:Adult; D000564:Ameloblastoma / Q000276:immunology* / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000378:metabolism; D005260:Female; D006801:Humans; D007573:Jaw Neoplasms / Q000276:immunology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D046888:Tissue Array Analysis / Q000379:methods*
chemical_list: D014408:Biomarkers, Tumor
keywords: Bcl-2; Ki67; ameloblastoma; cytokeratin; tissue microarray