title: Thyroid transcription factor-1 and cytokeratins 7 and 20 in pulmonary and breast carcinoma.
abstract: OBJECTIVE
  To evaluate the immunohistochemical expression of a lung epithelial gene transcription factor, thyroid transcription factor-1 (TTF-1), in lung and breast carcinoma in pulmonary cytologic preparations and to correlate the results with the expression of cytokeratin 7 (CK7) and 20 (CK20).
  
  
  METHODS
  Cell blocks of cytologic specimens were immunostained with antibodies to TTF-1, CK7 and CK20. Specimens included 41 primary lung carcinomas (21 adenocarcinomas, 8 squamous cell carcinomas and 12 small cell undifferentiated carcinomas) and 6 metastatic breast adenocarcinomas.
  
  
  RESULTS
  The lung adenocarcinomas showed nuclear reactivity for TTF-1 in 76% (16/21) of the cases and a staining combination of CK7+/CK20- in 95% (20/21) of the cases. Only one case was CK7+/CK20+. All the breast carcinomas were nonreactive to TTF-1, and all were CK7+/CK20-. The squamous cell carcinomas and small cell undifferentiated carcinomas showed TTF-1 positivity in 38% (3/8) and 83% (10/12), respectively.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Cincinnati Medical Center, Ohio, USA.
authors.forename: H A
authors.initials: HA
authors.lastname: Harlamert
authors.forename: J
authors.initials: J
authors.lastname: Mira
authors.forename: P A
authors.initials: PA
authors.lastname: Bejarano
authors.forename: R P
authors.initials: RP
authors.lastname: Baughman
authors.forename: M A
authors.initials: MA
authors.lastname: Miller
authors.forename: J A
authors.initials: JA
authors.lastname: Whitsett
authors.forename: R
authors.initials: R
authors.lastname: Yassin
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D014408:Biomarkers, Tumor; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D018288:Carcinoma, Small Cell / Q000378:metabolism / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology; D005260:Female; D018398:Homeodomain Proteins / Q000032:analysis; D006801:Humans; D007381:Intermediate Filament Proteins / Q000032:analysis*; D053554:Keratin-20; D053552:Keratin-7; D007633:Keratins / Q000032:analysis*; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D009687:Nuclear Proteins / Q000032:analysis*; D013961:Thyroid Gland / Q000737:chemistry / Q000473:pathology; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; D018398:Homeodomain Proteins; D007381:Intermediate Filament Proteins; C507499:KRT20 protein, human; C507497:KRT7 protein, human; D053554:Keratin-20; D053552:Keratin-7; C000614412:NKX2-1 protein, human; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors; D007633:Keratins