title: Expression pattern of CK7, CK20, CDX-2, and villin in intestinal-type sinonasal adenocarcinoma.
abstract: BACKGROUND
  Intestinal-type sinonasal adenocarcinoma (ITAC) is an uncommon neoplasm, which resembles adenocarcinoma of the gastrointestinal tract. ITAC occurs sporadically or in association with occupational exposure to hardwood dust and other agents.
  
  
  OBJECTIVE
  To investigate the phenotype and possible pathogenetic mechanisms of primary sinonasal and nasopharyngeal adenocarcinomas by staining for cytokeratin 7 (CK7), CK20, CDX-2, and villin.
  
  
  METHODS
  Twelve sporadic sinonasal and nasopharyngeal adenocarcinomas were stained with monoclonal antibodies to CK7, CK20, CDX-2, and villin. The ITACs were classified as papillary, colonic, solid, mixed, or mucinous types.
  
  
  RESULTS
  The diagnosis of ITAC was confirmed in 10 cases: five were colonic type and five were papillary. One was a sinonasal papillary low grade adenocarcinoma, and one a papillary nasopharyngeal adenocarcinoma, and these tumours were CK7 positive, but CK20, CDX-2, and villin negative. All ITACs were positive for CK20, CDX-2, and villin, and six were CK7 positive. One ITAC had a focus of intestinal metaplasia away from the invasive carcinoma.
  
  
  CONCLUSIONS
  Sinonasal ITACs have a distinctive phenotype, with all cases expressing CK20, CDX-2, and villin. Most ITACs also express CK7, although a proportion of tumours are CK7 negative. ITAC seems to be preceded by intestinal metaplasia of the respiratory mucosa, which is accompanied by a switch to an intestinal phenotype. Although ITACs are morphologically similar, differences in cytokeratin expression patterns suggest two distinct types. The expression pattern of CK7, CK20, CDX-2, and villin positive may be useful in separating these tumours from other non-ITAC adenocarcinomas of the sinonasal tract and nasopharynx.
authors.affiliation: Department of Pathology, University Health Network, Toronto M4N 3M5, Ontario, Canada.
authors.forename: M T
authors.initials: MT
authors.lastname: Kennedy
authors.forename: R C K
authors.initials: RC
authors.lastname: Jordan
authors.forename: K W
authors.initials: KW
authors.lastname: Berean
authors.forename: B
authors.initials: B
authors.lastname: Perez-Ordoñez
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D000071616:CDX2 Transcription Factor; D002352:Carrier Proteins / Q000032:analysis; D005260:Female; D018398:Homeodomain Proteins / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007221:Industry; D007381:Intermediate Filament Proteins / Q000032:analysis; D007413:Intestinal Mucosa / Q000473:pathology; D007414:Intestinal Neoplasms / Q000737:chemistry* / Q000473:pathology; D053554:Keratin-20; D053552:Keratin-7; D007633:Keratins / Q000032:analysis*; D008297:Male; D008679:Metaplasia; D008840:Microfilament Proteins / Q000032:analysis; D008875:Middle Aged; D009669:Nose Neoplasms / Q000737:chemistry* / Q000473:pathology; D009784:Occupational Diseases / Q000473:pathology; D010255:Paranasal Sinus Neoplasms / Q000737:chemistry* / Q000473:pathology; D015534:Trans-Activators; D014934:Wood
chemical_list: D014408:Biomarkers, Tumor; D000071616:CDX2 Transcription Factor; D002352:Carrier Proteins; D018398:Homeodomain Proteins; D007381:Intermediate Filament Proteins; C507499:KRT20 protein, human; C507497:KRT7 protein, human; D053554:Keratin-20; D053552:Keratin-7; D008840:Microfilament Proteins; D015534:Trans-Activators; C026615:villin; D007633:Keratins