Comparison of ThinPrep preparations to other preparation types in gastrointestinal cytology: observations from the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytology.
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.
Clayton
Amy C
AC
Division of Anatomic Pathology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA. clayton.amy@mayo.edu
Bentz
Joel S
JS
Wasserman
Patricia G
PG
Schwartz
Mary R
MR
Souers
Rhona J
RJ
Chmara
Beth Anne
BA
Laucirica
Rodolfo
R
Clary
Karen M
KM
Moriarty
Ann T
AT
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