title: Thyroid transcription factor 1: a marker for lung adenoarinoma in body cavity fluids.
abstract: BACKGROUND
  Adenocarcinomas are the most common epithelial malignancies in body cavity fluids. Subclassification of adenocarcinomas according to primary site can be a challenging task. Thyroid transcription factor 1 (TTF-1) is a nuclear transcription factor that is expressed in normal lung, in thyroid, and in their neoplasms. Because thyroid carcinomas rarely metastasize to the serosal surfaces, the authors used TTF-1 as a marker to distinguish adenocarcinomas of the lung from carcinomas of other organs.
  
  
  METHODS
  The authors studied 113 body cavity fluids (92 pleural fluid samples and 21 ascitic samples) from 113 patients with a diagnosis of adenocarcinoma on the basis of routine cytology. The primary sites of origin were confirmed clinically or histologically for all patients. There were 39 adenocarcinomas of the lung, 24 adenocarcinomas of the breast, 34 adenocarcinomas of the genitourinary tract, and 16 adenocarcinomas of the gastrointestinal tract. Archival Papanicolaou-stained, cytocentrifuged slides were used without destaining for immunocytochemistry with the monoclonal TTF-1 antibody using a commercial available method.
  
  
  RESULTS
  TTF-1 was expressed in 21 of 39 lung adenocarcinomas (54%). Intense nuclear staining was present in tumor cells that occurred in groups or in isolated form. In contrast, none of the other types of adenocarcinomas expressed TTF-1.
  
  
  CONCLUSIONS
  TTF-1 is a highly specific marker for adenocarcinomas of the lung in body cavity fluids. Immunocytochemistry using this antibody can be performed easily on archival Papanicolaou-stained, cytocentrifuged slides of fluid specimens.
authors.affiliation: Department of Pathology, University of Miami/Jackson Memorial Medical Center, Miami, Florida 33136, USA.
authors.forename: Carmen
authors.initials: C
authors.lastname: Gomez-Fernandez
authors.forename: Merce
authors.initials: M
authors.lastname: Jorda
authors.forename: Patricia I
authors.initials: PI
authors.lastname: Delgado
authors.forename: Parvin
authors.initials: P
authors.lastname: Ganjei-Azar
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D012680:Sensitivity and Specificity; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; C000614412:NKX2-1 protein, human; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors