title: Utility of napsin A and thyroid transcription factor 1 in differentiating metastatic pulmonary from non-pulmonary adenocarcinoma in pleural effusion.
abstract: OBJECTIVE
  It was our aim to evaluate the usefulness of napsin A and thyroid transcription factor 1 (TTF-1) in the differential diagnosis of metastatic pulmonary and non-pulmonary adenocarcinomas (ACs) in pleural effusion.
  
  
  METHODS
  A total of 84 pleural effusion fluid cell blocks were collected from metastatic ACs. There were 53 pulmonary ACs and 31 non-pulmonary ACs. Immunohistochemical staining was performed with antibodies against napsin A and TTF-1.
  
  
  RESULTS
  Napsin A was positive in 44/53 (83%) cases of pulmonary ACs, and TTF-1 was positive in 30/53 (57%) cases of pulmonary ACs. All non-pulmonary ACs were negative for napsin A and TTF-1. Napsin A showed a reactivity in >75% of the tumor cells in 36 of the 44 positive cases (82%), whereas TTF-1 showed a reactivity in >75% of the tumor cells only in 6 of the 30 positive cases (20%; p < 0.01). Poorly differentiated pulmonary ACs expressed napsin A (73%) more frequently than TTF-1 (53%), but this was not statistically significant (p = 0.45).
  
  
  CONCLUSIONS
  We conclude that napsin A is superior to TTF-1 with regard to distinguishing between metastatic pulmonary and non-pulmonary ACs in cell blocks prepared from malignant pleural effusions.
authors.affiliation: Department of Pathology, Jeju National University Medical School, Jeju, Korea.
authors.forename: Jo-Heon
authors.initials: JH
authors.lastname: Kim
authors.forename: Young-Sill
authors.initials: YS
authors.lastname: Kim
authors.forename: Yoo-Duk
authors.initials: YD
authors.lastname: Choi
authors.forename: Ji-Shin
authors.initials: JS
authors.lastname: Lee
authors.forename: Chang-Soo
authors.initials: CS
authors.lastname: Park
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000378:metabolism* / Q000473:pathology; D016282:Aspartic Acid Endopeptidases / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism; D003937:Diagnosis, Differential; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000378:metabolism* / Q000473:pathology; D009362:Neoplasm Metastasis; D009687:Nuclear Proteins / Q000378:metabolism*; D016066:Pleural Effusion, Malignant / Q000473:pathology*; D012189:Retrospective Studies; 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; D016282:Aspartic Acid Endopeptidases; C498549:NAPSA protein, human