title: Papanicolaou and thin-layer cervical cytology with colposcopic biopsy control. A comparison.
abstract: OBJECTIVE
  To compare the accuracy of conventional Papanicolaou and fluid-based, thin-layer cervical cytology.
  
  
  METHODS
  Cervical cytology was performed in duplicate on women who presented for cervical screening. Papanicolaou and thin-layer (ThinPrep, Cytyc Corp., Boxborough, Massachusetts) cytologic samples were collected simultaneously using a split-sample method. Cytologic slides were read and reported independently. Clinical follow-up was based on the most abnormal result. Colposcopy was performed as clinically indicated, and biopsy results were compared with cytologic diagnoses.
  
  
  RESULTS
  Three thousand samples were compared. Papanicolaou and thin-layer results were significantly different (P = .0001), with identical diagnoses in 1,844 (61%) of patients. Eighty thin-layer (2.7%) and 177 Papanicolaou (5.9%) samples were read as limited or unsatisfactory (P < .0001). The rates of atypical squamous cells of undetermined significance (ASCUS) were not statistically different (P = .06). Thin-layer cytology was read more often as low grade squamous intraepithelial lesion (P = .001) or high grade squamous intraepithelial lesion (P = .006). Colposcopy with biopsy was performed on 291 patients. With ASCUS considered an abnormal result, thin-layer cytology was more sensitive (91% vs. 85%) but had lower positive predictive value (69% vs. 74%) than Papanicolaou cytology for the presence of cervical neoplasia.
  
  
  CONCLUSIONS
  Papanicolaou and thin-layer cervical cytology yielded significantly different information. Thin-layer cytology yielded significantly fewer unsatisfactory results and was more sensitive for identifying cervical intraepithelial neoplasia.
authors.affiliation: Department of Obstetrics and Gynecology, Mountain Area Health Education Center, Pathologists' Medical Laboratory, PA, Asheville, North Carolina, USA.
authors.forename: C Blair
authors.initials: CB
authors.lastname: Harkness
authors.forename: James P
authors.initials: JP
authors.lastname: Theofrastous
authors.forename: Stacey N
authors.initials: SN
authors.lastname: Ibrahim
authors.forename: Shelley L
authors.initials: SL
authors.lastname: Galvin
authors.forename: Hal C
authors.initials: HC
authors.lastname: Lawrence
mesh_terms: D000328:Adult; D001706:Biopsy; D002584:Cervix Uteri / Q000473:pathology*; D003127:Colposcopy; D003581:Cytodiagnosis; D005260:Female; D006801:Humans; D065006:Papanicolaou Test; D012680:Sensitivity and Specificity; D002583:Uterine Cervical Neoplasms / Q000473:pathology; D014626:Vaginal Smears; D002578:Uterine Cervical Dysplasia / Q000473:pathology