title: Diagnostic utility of CDX-2 expression in separating metastatic gastrointestinal adenocarcinoma from other metastatic adenocarcinoma in fine-needle aspiration cytology using cell blocks.
abstract: BACKGROUND
  CDX-2 gene is a transcription factor that is involved in the proliferation and differentiation of intestinal epithelial cells. Recent studies have shown that CDX-2 could be used as an immunohistochemical marker to differentiate metastatic gastrointestinal adenocarcinoma from other metastatic adenocarcinomas in surgical pathology. The objective of the current study was to investigate the diagnostic value of CDX-2 to separate metastatic gastrointestinal adenocarcinoma from other metastatic adenocarcinomas in fine-needle aspiration cytology (FNAC).
  
  
  METHODS
  Sixty-two FNAC specimens of metastatic adenocarcinomas with corresponding cell blocks were retrieved from the hospital computer system. There were 22 specimens of metastatic gastrointestinal adenocarcinoma, 20 specimens of metastatic pulmonary adenocarcinoma, and 20 specimens of metastatic adenocarcinomas from other sites, including 10 from the breast, 3 from the ovaries, 4 from the pancreas, and 3 from the prostate. Radiology and histologic evaluation confirmed all cases. Sections were immunostained for CDX-2 and thyroid transcription factor-1 (TTF-1) using a heat-induced epitope retrieval technique.
  
  
  RESULTS
  In metastatic gastrointestinal adenocarcinoma, CDX-2 demonstrated positive nuclear staining in 19 of 22 specimens (86%). Other specimens of metastatic adenocarcinoma were negative for CDX-2. TTF-1 expression was detected in 0%, 80%, and 0% of metastatic gastrointestinal adenocarcinoma, pulmonary adenocarcinoma, and other adenocarcinoma specimens, respectively.
  
  
  CONCLUSIONS
  The results of the current study demonstrated that CDX-2 is a sensitive and a specific marker to separate metastatic gastrointestinal adenocarcinoma from other metastatic adenocarcinomas in FNAC specimens.
authors.affiliation: Department of Pathology, Allegheny General Hospital, Pittsburgh, Pennsylvania, USA. redsaad2@hotmail.com
authors.forename: Reda S
authors.initials: RS
authors.lastname: Saad
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Essig
authors.forename: Jan F
authors.initials: JF
authors.lastname: Silverman
authors.forename: Yulin
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000378:metabolism / Q000556:secondary; D014408:Biomarkers, Tumor / Q000378:metabolism; D001707:Biopsy, Needle; D000071616:CDX2 Transcription Factor; D002467:Cell Nucleus / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D018398:Homeodomain Proteins / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D009687:Nuclear Proteins / Q000378:metabolism; D012680:Sensitivity and Specificity; D000074482:Thyroid Nuclear Factor 1; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D000071616:CDX2 Transcription Factor; D018398:Homeodomain Proteins; C000614412:NKX2-1 protein, human; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D015534:Trans-Activators; D014157:Transcription Factors