title: Digital image DNA cytometry: a useful tool for the evaluation of malignancy in biliary strictures.
abstract: BACKGROUND
  Cytologic evaluation of the biliary tract strictures is nowadays widely used for distinguishing between benign and malignant lesions but remains a challenge for some problematic cases. Digital Image cytometry (DNA-cytometry) helps cytopathologists to resolve some unclear situations.
  
  
  METHODS
  We have analysed 41 specimens of bile duct brushings obtained from patients during ERCP (11 benign cases, 7 suspicious for malignancy cases and 23 malignant cases) by DNA-cytometry and correlated them with the histological biopsy counterpart.
  
  
  RESULTS
  All eleven cytological and histological benign cases were DNA-diploid and among 22 patients with malignant cytological and histological diagnosis 21 were DNA-aneuploid. One case considered malignant by the cytopathologist revealed DNA-aneuploid but malignancy could not be confirmed by histology. The analysis of the suspicious for malignancy cases revealed that all DNA-aneuploid cases were malignant and all DNA-diploid cases were benign referring to the follow-up of the patients. The comparison between cytology alone and cytology combined with DNA-cytometry related to the histological diagnosis (gold standard) resulted in a sensitivity of 100% and a specificity of 79% for cytology alone; a specificity of 94% and a sensitivity 92% for DNA-cytometry and a specificity of 93% and a sensitivity of 100% with combined analyses. The positive predictive value was 90% for cytology, 96% for DNA-cytometry and for both analyses. The negative predictive value showed 100% for cytology, 89% for DNA-cytometry and 100% for combined studies.
  
  
  CONCLUSIONS
  Despite the limited number of patients involved in the study, the results obtained indicate an increased of specificity and of positive predictive value using DNA-cytometry. These results confirm the pertinence of these method for challenging cases, in conjunction with other available diagnostic tools.
authors.affiliation: Institut Universitaire de Pathologie, Bugnon 25, 1011 Lausanne, Switzerland. maria-chiara.osterheld@chuv.hospvd.ch
authors.forename: M C
authors.initials: MC
authors.lastname: Osterheld
authors.forename: S
authors.initials: S
authors.lastname: Andrejevic Blant
authors.forename: L
authors.initials: L
authors.lastname: Caron
authors.forename: R
authors.initials: R
authors.lastname: Braunschweig
authors.forename: G
authors.initials: G
authors.lastname: Dorta
authors.forename: H
authors.initials: H
authors.lastname: Bouzourene
authors.forename: A
authors.initials: A
authors.lastname: Mihaescu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001659:Biliary Tract / Q000166:cytology / Q000378:metabolism / Q000473:pathology*; D001661:Biliary Tract Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D004273:DNA, Neoplasm / Q000235:genetics; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D019044:Image Cytometry; D008297:Male; D008875:Middle Aged
chemical_list: D004273:DNA, Neoplasm