title: Presence of ghost cells and the Wnt signaling pathway in odontomas.
abstract: BACKGROUND
  Although it has been reported that ghost cells are present in odontomas, the generation mechanism of these cells is unclear. To evaluate the presence of ghost cells and involvement of the Wnt signaling pathway, we examined the expression of hard keratins, beta-catenin and Lef-1 in odontomas.
  
  
  METHODS
  Sixty-nine cases of odontoma were examined immunohistochemically with the use of antibodies against human hair proteins, beta-catenin and Lef-1.
  
  
  RESULTS
  Expression of hard keratins was found only in the cytoplasm of ghost cells in 46 (66.7%) of the 69 odontomas. Compound odontomas (78.8%) showed a higher incidence of ghost cells than complex odontomas (29.4%). Histopathologically, ghost cells were found within odontogenic epithelium adjacent to immature enamel and in the centre of Liesegang-ring-like calcified materials. Expression of beta-catenin and Lef-1 was observed in the cytoplasm and nucleus of odontogenic epithelial cells adjacent to the ghost cells in immature odontomas.
  
  
  CONCLUSIONS
  These findings suggest that odontoma is a hard keratin-expressing tumor-like lesion, and that the Wnt signaling pathway may be involved in the formation of ghost cells in odontomas.
authors.affiliation: Division of Pathology, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Saitama, Japan. akio.t@dent.meikai.ac.jp
authors.forename: Akio
authors.initials: A
authors.lastname: Tanaka
authors.forename: Motoyoshi
authors.initials: M
authors.lastname: Okamoto
authors.forename: Dai
authors.initials: D
authors.lastname: Yoshizawa
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ito
authors.forename: Patricia González
authors.initials: PG
authors.lastname: Alva
authors.forename: Fumio
authors.initials: F
authors.lastname: Ide
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kusama
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002467:Cell Nucleus / Q000648:ultrastructure; D002648:Child; D002675:Child, Preschool; D003593:Cytoplasm / Q000648:ultrastructure; D003743:Dental Enamel / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D005260:Female; D006801:Humans; D007633:Keratins / Q000032:analysis; D051821:Lymphoid Enhancer-Binding Factor 1 / Q000032:analysis; D008297:Male; D008339:Mandibular Neoplasms / Q000473:pathology; D008441:Maxillary Neoplasms / Q000473:pathology; D008875:Middle Aged; D009810:Odontoma / Q000473:pathology*; D015398:Signal Transduction / Q000502:physiology; D051153:Wnt Proteins / Q000032:analysis*; D051176:beta Catenin / Q000032:analysis
chemical_list: C495270:CTNNB1 protein, human; D051821:Lymphoid Enhancer-Binding Factor 1; D051153:Wnt Proteins; D051176:beta Catenin; D007633:Keratins