title: Comparison of ThinPrep preparations to other preparation types in gastrointestinal cytology: observations from the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytology.
abstract: BACKGROUND
  Differences in participant responses for ThinPrep (TP) and non-ThinPrep (NTP) preparations for gastrointestinal cytology challenges, which circulated in the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytology (CAP NGC), may help to identify performance variations between preparation types.
  
  
  OBJECTIVE
  To compare the performance of TP-prepared slides of gastrointestinal exfoliative cytology specimens to that of NTP preparations in the CAP NGC program.
  
  
  METHODS
  Participant responses between 2000 and 2007 were evaluated for esophageal wash/brush, gastric wash/brush, and biliary tract brush specimens with a reference diagnosis of adenocarcinoma, squamous cell carcinoma, carcinoid, or spindle cell neoplasm. ThinPrep challenges were compared with NTP preparations (conventional smears, cytospins) for discordant responses.
  
  
  RESULTS
  In all, 6023 pathologist responses and 3825 cytotechnologist responses were reviewed. Non-ThinPrep preparations comprised 93% (n = 11 588) of the challenges, while 7% (n = 912) were TP material. A match for a "positive/suspicious" diagnosis was seen in 88.5% of NTP and 95.9% of TP preparations (P < .001). These results were statistically significant when the specific reference diagnosis was adenocarcinoma (P < .001). Overall performance of cytotechnologists was not different from that of pathologists (89.2% versus 89.0%; P = .75). Cytotechnologists had better performance for detecting squamous cell carcinoma (96.3% versus 92.6%; P < .001), while pathologists had better performance for detecting spindle cell neoplasm (79.7% versus 42.9%; P < .001).
  
  
  CONCLUSIONS
  ThinPrep preparations performed significantly better than NTP preparations in gastrointestinal cytology specimens circulated in an interlaboratory comparison program. Performance varied by reference interpretation, with the best performance for the interpretation of adenocarcinoma. Cytotechnologists and pathologists performed at the same level overall, but with differences for the diagnosis of spindle cell neoplasm and squamous carcinoma.
authors.affiliation: Division of Anatomic Pathology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA. clayton.amy@mayo.edu
authors.forename: Amy C
authors.initials: AC
authors.lastname: Clayton
authors.forename: Joel S
authors.initials: JS
authors.lastname: Bentz
authors.forename: Patricia G
authors.initials: PG
authors.lastname: Wasserman
authors.forename: Mary R
authors.initials: MR
authors.lastname: Schwartz
authors.forename: Rhona J
authors.initials: RJ
authors.lastname: Souers
authors.forename: Beth Anne
authors.initials: BA
authors.lastname: Chmara
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Laucirica
authors.forename: Karen M
authors.initials: KM
authors.lastname: Clary
authors.forename: Ann T
authors.initials: AT
authors.lastname: Moriarty
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis*; D003581:Cytodiagnosis / Q000379:methods; D003584:Cytological Techniques; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis*; D006801:Humans; D007755:Laboratories, Hospital / Q000592:standards*; D010338:Pathology, Clinical / Q000379:methods*; D012955:Societies, Medical; D014481:United States