title: Nuclear β-catenin expression in basal cell adenomas of salivary gland.
abstract: BACKGROUND
  Nuclear localization of β-catenin is known in a wide variety of human neoplasms; however, there are few reports in basal cell adenoma of the salivary gland. Our objective was to confirm the nuclear localization of β-catenin in basal cell adenoma and to examine whether nuclear β-catenin expression could be a useful marker in the diagnosis of basal cell adenoma.
  
  
  METHODS
  To evaluate the nuclear localization of β-catenin in basal cell adenomas, immunohistochemistry (IHC) and mutation analysis of CTNNB1 were performed in 22 and 21 cases, respectively. Mutation analysis of CTNNB1 in exon 3 was performed by DNA direct sequencing. In a comparative study, IHC for β-catenin was also performed in 157 other salivary gland tumors.
  
  
  RESULTS
  Nuclear β-catenin expression was examined in 22 basal cell adenomas; scores were 2+ in 18 cases (81.8%), 1+ in three cases (13.6%), and 0 in one case (4.5%). Expression was localized in the basaloid myoepithelial cells. CTNNB1 mutation analysis was performed in 21 basal cell adenomas; mutations, including I35T and T41P, were detected in 11/21 (52%) cases. In comparison with other salivary gland tumors, one of three basal cell adenocarcinomas showed nuclear β-catenin expression, whereas there was no nuclear β-catenin expression in 154 other salivary gland tumors.
  
  
  CONCLUSIONS
  We demonstrated nuclear β-catenin expression and activation of the CTNNB1 gene in basal cell adenoma. Although nuclear β-catenin expression may be unable to distinguish basal cell adenoma from basal cell adenocarcinoma, it should be a helpful marker in the diagnosis of basal cell adenoma.
authors.affiliation: Department of Diagnostic Pathology, Kurume University Hospital, Kurume, Japan. akihiko4@med.kurume-u.ac.jp
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kawahara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Harada
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Abe
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Tomoki
authors.initials: T
authors.lastname: Taira
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Nakashima
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mihashi
authors.forename: Jun
authors.initials: J
authors.lastname: Akiba
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kage
mesh_terms: D021581:Active Transport, Cell Nucleus; D000236:Adenoma / Q000235:genetics / Q000378:metabolism*; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D002467:Cell Nucleus / Q000378:metabolism*; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010307:Parotid Neoplasms / Q000235:genetics / Q000378:metabolism*; D051176:beta Catenin / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; C495270:CTNNB1 protein, human; D051176:beta Catenin