Accuracy and Reproducibility of Estimating the Adequacy of the Squamous Component of Cervicovaginal Smears

Renshaw, Andrew A.; Friedman, M M; Rahemtulla, Amir; Granter, Scott R.; Dean, Barbara; Cronin, Janet A.; Jiroutek, Michael R.; Cibas, Edmund S.

doi:10.1093/ajcp/111.1.38

Cited by 30 publications

(22 citation statements)

References 7 publications

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“…Feedback from laboratory to clinician can achieve a great improvement. Despite the Bethesda System guidelines for specimen adequacy, intraobserver agreement on adequacy is poor, 26 and adequate cellularity of the conventional smear has never been satisfactorily resolved in the cytology literature.…”

Section: Specimen Adequacymentioning

confidence: 99%

Sampling, Sampling Errors and Specimen Preparation

et al. 2000

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Section: Specimen Adequacymentioning

confidence: 99%

Sampling, Sampling Errors and Specimen Preparation

et al. 2000

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“…However, consistent and reliable identification of these criteria has been questioned. 23,24 Following the introduction of LBC in the USA, TBS required a minimum of 5000 squamous cells on the slide for a LBC preparation to be regarded as adequate and provided comprehensive guidance on how the MACC should be determined. 10 It was recommended that a minimum of 10 microscopic fields, usually at ×40 objective magnification, should be assessed along a diameter that includes the centre of the preparation and an average number of cells per field estimated.…”

Section: Discussionmentioning

confidence: 99%

A study of cellular counting to determine minimum thresholds for adequacy for liquid-based cervical cytology using a survey and counting protocol

Kitchener

Gittins

Desai³

et al. 2015

Health Technology Assessment

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BackgroundLiquid-based cytology (LBC) for cervical screening would benefit from laboratory practice guidelines that define specimen adequacy for reporting of slides. The evidence base required to define cell adequacy should incorporate both ThinPrep™ (TP; Hologic, Inc., Bedford, MA, USA) and SurePath™ (SP; BD Diagnostics, Burlington, NC, USA), the two LBC systems used in the UK cervical screening programmes.ObjectivesThe objectives of this study were to determine (1) current practice for reporting LBC in England, Wales and Scotland, (2) a reproducible method for cell counting, (3) the cellularity of slides classified as inadequate, negative or abnormal and (4) the impact of varying cellularity on the likelihood of detecting cytological abnormalities.DesignThe study involved four separate arms to pursue each of the four objectives. (1) A questionnaire survey of laboratories was conducted. (2) A standard counting protocol was developed and used by three experienced cytopathologists to determine a reliable and reproducible cell counting method. (3) Slide sets which included a range of cytological abnormalities were each sent to three laboratories for cell counting to study the correlation between cell counts and reported cytological outcomes. (4) Dilution of LBC samples by fluid only (unmixed) or by dilution with a sample containing normal cells (mixed) was performed to study the impact on reporting of reducing either the total cell count or the relative proportion of abnormal to normal cells.SettingThe study was conducted within the cervical screening programmes in England, Wales and Scotland, using routinely obtained cervical screening samples, and in 56 participating NHS cervical cytology laboratories.ParticipantsThe study involved only routinely obtained cervical screening samples.InterventionsThere was no clinical intervention.Main outcome measuresThe main outcome measures were (1) reliability of counting method, (2) correlation of reported cytology grades with cellularity and (3) levels of detection of abnormal cells in progressively diluted cervical samples.ResultsLaboratory practice varied in terms of threshold of cellular adequacy and of morphological markers of adequacy. While SP laboratories generally used a minimum acceptable cell count (MACC) of 15,000, the MACC employed by TP laboratories varied between 5000 and 15,000. The cell counting study showed that a standard protocol achieved moderate to strong inter-rater reproducibility. Analysis of slide reporting from laboratories revealed that a large proportion of the samples reported as inadequate had cell counts above a threshold of 15,000 for SP, and 5000 and 10,000 for TP. Inter-rater unanimity was greater among more cellular preparations. Dilution studies demonstrated greater detection of abnormalities in slides with counts above the MACC and among slides with more than 25 dyskaryotic cells.ConclusionsVariation in laboratory practice demonstrates a requirement for evidence-based standards for designating a MACC. This study has indicated that a MACC of 15,000 and 5000 for SP and TP, respectively, achieves a balance in terms of maintaining sensitivity and low inadequacy rates.Future workThe findings of this study should inform the development of laboratory practice guidelines.FundingThe National Institute for Health Research Health Technology Assessment programme.

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“…Unsatisfactory samples lead to increased health care costs (11) and unsatisfactory samples have a higher incidence of cytologic abnormalities on repeat examination (12,13). Despite attempts to improve the estimation of specimen adequacy on slides (14,15), there have been few if any attempts to automate the process, determine adequacy before slide review, or determine adequacy at the point of care. Here, we report a rapid, extremely sensitive, and specific assay for the determination of liquid based cervical cytology specimen adequacy that can be performed in the laboratory or possibly at the point of care.…”

Section: Discussionmentioning

confidence: 99%

“…Further, the classifications still require a semiquantitative assessment of the number and types of cells including ectocervical cells and obscuring inflammatory cells (PMNs) though some have suggested that this remains an inexact assessment (11,14,17). Surprisingly, the Bethesda 2001 guidelines still rely on cytotechnologist or cytopathologist visual review to make this quantitative assessment.…”

Section: Discussionmentioning

confidence: 99%

Rapid, high throughput determination of cervical cytology specimen adequacy using a capillary‐based cytometer

Polina¹,

Sturgis

Patterson³

et al. 2007

Cytometry Part B Clinical

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Despite the fact that compact instruments dedicated to counting cells are readily available especially in hematology, liquid-based cervical cytology specimen adequacy is still determined by pathologist review following the preparation of slides. More than 100 liquid-based cervical cytology specimens collected in ThinPrep vials were processed into slides for diagnosis and assessment of specimen adequacy using the Bethesda 2001 criteria. Residual liquid (100 lL) was transferred to a single well of a 96-well plate and run in a capillary cytometer (Guava Technologies, Hayward, CA) with forward scatter and side scatter detectors. We determined that the sensitivity and specificity of this assay for unsatisfactory samples was 100% and 97%, respectively, compared with cytopathologic examination. The difference in the concentration of ectocervical cells/lL (EPU) between samples determined to be unsatisfactory by virtue of less than an estimated 5,000 cells per slide and satisfactory samples were statistically significant (P < 0.001). Here, we report the use of this rapid specimen adequacy assay on a small, capillary based, personal cytometer. Use of this instrument reduced the amount of sample required by >90% and reduced the average per sample assay time from 120 s to 10 s compared with flow cytometry. q 2007 Clinical Cytometry Society Key terms: cervical cytology; ThinPrep; liquid-based cytology; specimen adequacy; unsatisfactory; Bethesda System How to cite this article: Polina R, Sturgis C, Patterson J, Patterson BK. Rapid, high throughput determination of cervical cytology specimen adequacy using a capillary-based cytometer. Cytometry Part B 2008; 74B: 133-136.

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Accuracy and Reproducibility of Estimating the Adequacy of the Squamous Component of Cervicovaginal Smears

Abstract: A b s t r a c t In the Bethesda

Cited by 30 publications

References 7 publications

Sampling, Sampling Errors and Specimen Preparation

Sampling, Sampling Errors and Specimen Preparation

A study of cellular counting to determine minimum thresholds for adequacy for liquid-based cervical cytology using a survey and counting protocol

Rapid, high throughput determination of cervical cytology specimen adequacy using a capillary‐based cytometer

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