title: An immunohistochemical study of keratin expression in ameloblastoma from a Kenyan population.
abstract: OBJECTIVE
  Ameloblastomas appear to exhibit biological heterogeneity and, except in the case of malignancy, histological appearances that do not always allow their behaviour to be predicted. The aim of this study was to assess keratin expression in African ameloblastomas and to correlate this with their clinical and histological features.
  
  
  METHODS
  Expression of simple keratins 7, 8, 18 and 19; cornification keratins 1 and 10; basal and differentiation keratins 5 and 14 and hyperproliferation-related keratins 6 and 16 in 14-39 cases of ameloblastoma was assessed by immunohistochemical methods.
  
  
  RESULTS
  There was patchy expression of keratin 7 in the suprabasal and stellate reticulum-like cells in some cases. All cases showed similar weak expression for keratins 8 and 18 in suprabasal and stellate reticulum-like cells but none showed keratin 1 or 10 expression. There was intense expression of keratins 5, 14 and 19 by all tumour cells suggesting that they may retain basal cell characteristics with a potential for proliferation. No consistent relationship was seen between histological types and keratin expression pattern. However, keratins 6 and 16, expressed by suprabasal and stellate reticulum-like cells, showed a marked variation within and between cases, with the highest levels of expression in squamous strands.
  
  
  CONCLUSIONS
  We propose that squamous strands may represent the sites of most active growth within individual tumours and expression of keratins 6, 16 and 19 may be predictors of rapid growth. There is a need for further investigation of this in longitudinal clinical studies.
authors.affiliation: Oral Diseases Research Centre, St Bartholomew's and the Royal London School of Medicine and Dentistry, Whitechapel, UK.
authors.forename: M N
authors.initials: MN
authors.lastname: Ong'uti
authors.forename: G L
authors.initials: GL
authors.lastname: Howells
authors.forename: D M
authors.initials: DM
authors.lastname: Williams
mesh_terms: D000293:Adolescent; D000328:Adult; D000564:Ameloblastoma / Q000737:chemistry* / Q000378:metabolism / Q000473:pathology; D000911:Antibodies, Monoclonal; D016009:Chi-Square Distribution; D002648:Child; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007573:Jaw Neoplasms / Q000737:chemistry* / Q000378:metabolism / Q000473:pathology; D007633:Keratins / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D011379:Prognosis; D018709:Statistics, Nonparametric
chemical_list: D000911:Antibodies, Monoclonal; D009363:Neoplasm Proteins; D007633:Keratins