title: The expression profiles of acidic epithelial keratins in ameloblastoma.
abstract: OBJECTIVE
  To characterize the subtypes of ameloblastoma by differentiation markers.
  
  
  METHODS
  Expression of 9 major acidic epithelial keratins was immunohistochemically examined in 28 ameloblastomas.
  
  
  RESULTS
  Keratin 15 (K15) expression patterns corresponded to histological variants: follicular, plexiform and acanthomatous. Tumor nests comprising K15-expressing basal cells mimicked oral epithelium or dental lamina, and tumor nests comprising K15-negative basal cells mimicked outer enamel epithelium. Keratin 19 (K19) was consistently expressed in solid/multicystic ameloblastoma and unicystic ameloblastoma, while peripheral ameloblastoma and desmoplastic ameloblastoma contained K19-negative cells.
  
  
  CONCLUSIONS
  The 4 current subtypes had unvaried expression patterns within each group. However, they could be divided into 2 groups by K19 expression pattern: solid/multicystic and unicystic versus extraosseous/peripheral and desmoplastic. K15 expression pattern represented various types of differentiation for tumor nests mimicking tooth germ and oral epithelium. The results clarify the homogeneity and heterogeneity of ameloblastoma cell lineage and differentiation.
authors.affiliation: Section of Oral Pathology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Samir Kumar
authors.initials: SK
authors.lastname: Pal
authors.forename: Kei
authors.initials: K
authors.lastname: Sakamoto
authors.forename: Tadanobu
authors.initials: T
authors.lastname: Aragaki
authors.forename: Takumi
authors.initials: T
authors.lastname: Akashi
authors.forename: Akira
authors.initials: A
authors.lastname: Yamaguchi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000564:Ameloblastoma / Q000145:classification / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000032:analysis; D015820:Cadherins / Q000032:analysis; D002454:Cell Differentiation; D019070:Cell Lineage; D003743:Dental Enamel / Q000473:pathology; D004847:Epithelial Cells / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053535:Keratin-13 / Q000032:analysis; D053547:Keratin-14 / Q000032:analysis; D053569:Keratin-15 / Q000032:analysis; D053536:Keratin-16 / Q000032:analysis; D053537:Keratin-17 / Q000032:analysis; D053538:Keratin-18 / Q000032:analysis; D053539:Keratin-19 / Q000032:analysis; D015603:Keratinocytes / Q000473:pathology; D053530:Keratins, Type I / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000473:pathology; D014083:Tooth Germ / Q000473:pathology; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D015820:Cadherins; C507426:KRT13 protein, human; C507540:KRT14 protein, human; C116015:KRT15 protein, human; C507431:KRT16 protein, human; C488421:KRT18 protein, human; D053535:Keratin-13; D053547:Keratin-14; D053569:Keratin-15; D053536:Keratin-16; D053537:Keratin-17; D053538:Keratin-18; D053539:Keratin-19; D053530:Keratins, Type I