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Home > Physicians > Molecular DNA Testing & Women`s Health > Cervical Cytology:Pap Smear - ThinPrep® Characteristics
Common changes associated with ThinPrep® morphology
- Key difference is the wet fixation
- Cell size, related to the cells placed into solution
- Smear Pattern, no longer smearing cellular material across the glass slide
- Specimen Background, unique characteristics
Wet Fixation
- Enhanced cytoplasmic detail
- Enhanced nuclear detail. Optimized fixation, no longer smearing the cells onto a dry glass slide. Sample rinsed directly into a fluid solution.
- Wet fixation allows for more variability in nuclear staining. The chromatin detail is more readily appreciated and can appear as hypo- and hyperchromatic nuclei with the same case.
Cell Size
- "Proportionally" smaller cells: inherent difference with alcohol fixation eliminated air-drying artifact.
- Single cells are more prominent: Single cell populations are not created, just more noticeable in the background.
- Cells round up in solution: physical properties, similar to non-gyn presentation.
Smear Pattern
- Mechanical artifacts associated with pulling the cells across the slide have been eliminated
- Cellular material is not pulled out in mucus - chance to establish new pattern recognition for ThinPrep®. Endocervical cells will be distributed throughout cell deposit and not caught up in mucus.
- Tissue architecture is maintained throughout the slide processing. Architecture is not destroyed, only the relationships of the cell groupings have been altered.
Specimen Background
- Specimen background is cleaner as a result of the filtration process. Microscopically you will see more light passing through the slide.
- Fluid collection causes the cellular debris to clump
- Background provides clues. Initially, ThinPrep® takes more vigilance when screening. More information per field. Information is typically obscured on the Conventional Pap Smear but is more easily identified in the background on a ThinPrep® slide.
- "Ratty" background can be advantageous during diagnosis: infectious agents, cytolysis, disease should be considered. Tumor diathesis, blood, cytolysis will be still be present on the slide and should be used in the differential diagnosis.
- Over 15,000,000 samples processed
- Over 282,000 specimens evaluated in peer-review studies
- Over 16,500 US physicians rinsing
- Over 700 US laboratories processing
- Over 200 US health plans cover the ThinPrep Pap Test
Improved sensitivity in clinical trail: 65% increase in screening population, and 6% increase in high-risk population.
Improved specimen adequacy with routine use: 35% reduction in "Satisfactory by limited by" specimens and 73% reduction in "Unsatisfactory" specimens.
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