Performance of the AutoPap Primary Screening System in the detection of high-risk cases in cervicovaginal smears

OBJECTIVE: To assess the performance of the AutoPap Primary Screening System (APSS) (TriPath Imaging, Inc., Burlington, North Carolina, U.S.A.) for the detection of high grade cervical squamous intraepithelial lesions and invasive cervical cancer. STUDY DESIGN: A total of 14,779 consecutive conventional Pap smears were processed by the APSS. All slides designated as "Review" by the device were manually screened according to the Bethesda System. The ranking scores obtained from the device were compared with the cytologic interpretations in all cases and with the final histologic diagnoses in the cases with cytologic severe abnormalities. RESULTS: The device classified 10,349 slides as Review (78%) and 2,912 (22%) as "No Further Review." In the 78% Review cases, the samples were ranked in descending order of potential abnormality, broken into quintiles. The correlation between the slide quintile ranks and the manual cytologic diagnosis indicated that 90% of abnormal smears were categorized by the device as in the first and second quintile rank, and the correlation between the rank report of the device and the histologic diagnosis showed that all cases of HSIL or invasive carcinoma were in the top two ranks. No significant abnormalities were observed in any of the smears categorized as No Further Review. CONCLUSION: This study confirmed the effectiveness of APSS for the detection of Pap smears with severe abnormalities.     

Use of automated primary screening on liquid-based, thin-layer preparations

OBJECTIVE: To evaluate the accuracy of the AutoPap System (TriPath Imaging, Inc., Burlington, North Carolina, U.S.A.) (TriPath) in screening AutoCyte PREP liquid-based, thin-layer preparations by comparing the final cytologic diagnoses with instrument slide classification results. STUDY DESIGN: A total of 9,665 AutoCyte PREP thin-layer slides were first independently screened to establish a final cytologic diagnosis (reference diagnosis). The slides were then processed on the AutoPap System. Each slide successfully processed was reported into result categories. The generated report gave a ranking score for each slide designated for "review." Slides designated "no further review" (NFR) were also listed in the report. The reported results were then compared to the reference cytologic diagnoses. RESULTS: Of 9,665 slides initially submitted to the AutoPap, 8,688 (90.8%) were qualified for scanning, and 884 (9.2%) were definitely classified as process review or rerun and excluded from the study. Of high grade squamous intraepithelial lesions and greater (HSIL+), 85.2% were ranked in the first rank, 12.7% in the second, one (2.1%) in the third, none in the fourth and fifth and none in the NFR category. Of low grade squamous intraepithelial lesions, 47.4% were ranked in the first rank, 20.8% in the second, 10.6% in the third, 10.1% in the fourth, 5.3% in the fifth and 5.8% in NFR. Of atypical squamous cells of undetermined significance and atypical glandular cells of undetermined significance, 53.6% were ranked in the first rank, 22.5% in the second, 12.4% in the third, 5.4% in the fourth, 3.8% in the fifth and 2.3% in NFR. Considering a cutoff value at < or = 3rd rank, 84% of cervical abnormalities (RR 6.52, 95% CI 4.96-8.66) and 100% of HSIL+ were identified. CONCLUSION: The AutoPap demonstrates a high capability for detecting cervical abnormalities on AutoCyte PREP thin-layer slides. HSIL+ was associated with the highest instrument scores.     

Inadequate cervical smears: results of an educational slide exchange scheme

Fifty-six slides, predominantly inadequate and of varying difficulty, were circulated to 12 laboratories as an educationally based slide exchange scheme. Three slides failed to achieve an agreed majority consensus opinion. Seventy percent of participants agreed with the consensus opinion in 80% of slides. Of the slides originally reported as inadequate, the consensus diagnosis was inadequate in 78%, negative in 12% and abnormal in 10%. The latter included two cases of high-grade dyskaryosis. There was good agreement for the two most frequent causes of inadequacy in submitted slides (obscured and poor cellularity). There was poor consistency in reporting the presence or absence of endocervical and immature squamous metaplastic cells, to an extent that questions their use in the assessment of smear adequacy. Three inadequate slides on consensus opinion were associated with subsequent cervical intraepithelial neoplasia (grade III) or invasive squamous cell carcinoma. In the latter case, the slide had originally been reported as negative by the submitting laboratory.     

Split-sample analysis of discarded cells from liquid-based Pap smear sampling devices

OBJECTIVE: To examine cells that were retained on sampling devices used to collect ThinPrep (Cytyc Corp., Boxborough, Massachusetts, U.S.A) Pap smears in order to evaluate both the number and significance of cells that are routinely discarded with these devices after liquid-based specimens are collected. STUDY DESIGN: One hundred Pap smears from 100 women were prospectively procured after gynecologic Pap smears were collected for the ThinPrep Pap test. The sampling end of the collection devices was cut off and placed in a vial that contained SUREPATH preservative fluid (TriPath Imaging, Inc., Burlington, North Carolina, U.S.A). The residual cell samples were processed using the SurePath PREPSTAIN slide processor (TriPath). A single liquid-based slide was prepared from the sampling devices from each of the 100 specimens collected. The slides produced from the discarded devices were reviewed for the following: squamous cells, endocervical component, epithelial cell abnormalities and miscellaneous findings. The slides prepared from the "throw-away" (TA) material were subsequently compared with the primary ThinPrep Pap smear slide. RESULTS: Twenty-five percent of the TA samples had an equal or greater number of squamous cells per high-power microscopic field when compared to the primary ThinPrep slide, with 8% of the TA slides demonstrating greater overall cellularity. An endocervical component was present on 27 of 66 cervical samples (40.9%). Three of five cases (60%) interpreted as atypical squamous cells of undetermined significance had similar cells on the TA slides. Two cases of atypical glandular cells of undetermined significance had no abnormal cells on the TA slides. Twelve of 14 cases (85.71%) of low grade squamous intraepithelial lesion contained similar cells on the TA slides. Two of four cases (50%) of high grade squamous intraepithelial lesion also had similar abnormal cells on the TA slides. Miscellaneous findings included 1 case of benign endometrial cells and 4 Candida infections present on both preparations, along with 1 case of Trichomonas vaginalis organisms present on the ThinPrep slide only. In 1 specimen, several multinucleated histiocytic giant cells were present only on the TA slide. CONCLUSIONS: Specimens prepared from TA collecting devices used for the ThinPrep Pap test are less sensitive than the primary specimen for the detection of cervical lesions. This is in contrast to split-sample studies involving ThinPrep and conventional smears. Our study documented the presence of normal and abnormal cells discarded from ThinPrep sampling devices in a high percentage of cases. Discarded abnormal cells on the TA slides were, however, few when compared to the primary specimen, with only 1 exception involving a high grade lesion.     

Evaluation of the FocalPoint GS system performance in an Italian population-based screening of cervical abnormalities

OBJECTIVE: To evaluate the FocalPoint Location-Guided Screening (FPGS) performance in computer-assisted primary screening of Papanicolaou-stained cervicovaginal smears. STUDY DESIGN: A total of 37,306 routine consecutive conventional Pap slides were prospectively processed on the FPGS. Each slid designated by the instrument as Review was reported according to results obtained using a GS Review Station. Subsequently, all slides under went conventional manual rapid screening and reported results were compared. RESULTS: Of the slides initially submitted to the FPGS, 34,004 (91.15%) were qualified for scanning. Within these slides, the system classified 7,399 (21.8%) as needing No Further Review and ranked to Review the remaining 26,605 (78.2%). Of the 418 cellular abnormalities found, 409 were classified for Review by FPGS and 9 minor grade lesions were classified in the "No Further Review" population. Overall, 352 (86%) of atypical squamous cell (ASC)+ were ranked in high-score quintiles, including 96 (94%) of the 102 high-grade squamous intraepithelial lesion (HSIL) or worse. Location-guided software identified cellular abnormalities, in the automatically selected fields of view, in 378 (92%) of the ranked abnormal slides, showing a sensitivity > 95% on SILs. CONCLUSION: Slide ranking and location-guided screening features are of value in detecting and triaging abnormal smears.     

Quality control in cervicovaginal cytology by cytohistological correlation

N. Izadi‐Mood, S. Sarmadi and S. Sanii
Quality control in cervicovaginal cytology by cytohistological correlation Objective: Frequent studies attest to the correlation of cytological interpretations with defined histopathological entities. Nevertheless, as part of quality control, cytology laboratories are required to compare Papanicolaou smear reports with those of cervical biopsies to search for discrepancies. We have attempted to determine and categorize the causes of existing discrepancies in our laboratory in order to clarify the source of errors. Methods: We reviewed 670 cervical smears that were paired with subsequent punch biopsy or endocervical curettage samples, obtained within 2 months of the cytology, and found out that 60 smear‐biopsy pairs were discrepant regarding the diagnosis. These cases were categorized into four error groups after careful re‐evaluation of the original smear and biopsy slides. Results: In 51 (85%) of 60 cervical smear‐biopsy pairs with reports that disagreed, the initial diagnoses of both cervical smear and biopsy were confirmed by the review opinion; in these cases, cytology and biopsy ‘sampling errors’ were responsible for 40 and 11 instances of discrepancy, respectively. Seven cases (11.1%) were discrepant due to ‘smear interpretation errors’ and consisted of five cases with initial under‐diagnosis and two cases with initial over‐diagnosis. One case (1.7%) was due to ‘screener error’. In another case, discordance was due to cervical ‘biopsy interpretation error’, with initial over‐diagnosis as squamous intraepithelial lesion. Conclusion: In this retrospective study, we determined the causes of cytohistological discrepancies in cervical samples. The main explanation for discrepancy was ‘sampling error’.     

Use of the ThinPrep Imaging System for internal quality control of cervical cytology

T. Heard, A. Chandra, G. Culora, S.S. Gupta, A. Herbert and M. Morgan
Use of the ThinPrep Imaging System for internal quality control of cervical cytology Objective: To audit the use of the ThinPrep Imaging System (TIS) for internal quality control (IQC) in the place of rapid review (RR), and to compare its performance with routine primary screening. Method: During 9 months, 16 462 ThinPrep slides were processed by TIS. Slides were initially reviewed using the TIS review scope, as recommended by the manufacturer: 22 fields of view were observed and, if considered abnormal, a full microscopic review was conducted using the review scope. Different biomedical scientists (BMSs), working on each procedure in rotation, performed batches of TIS‐assisted quality control and routine primary screening independently on unmarked slides. Any slides with abnormalities detected by either method were referred to a consultant pathologist or advanced BMS practitioner for a final report. TIS results were compared with both previous records of RR and routine primary screening carried out on the same slides. We used the UK terminology in which ‘dyskaryosis’ is equivalent to squamous intraepithelial lesion (SIL) and borderline to atypical (including squamous and glandular cells). Results: TIS preview detected significantly more high‐grade dyskaryosis compared with RR during the previous 4 years: 2.0–4.2 compared with 0.1–1.8 detected per 1000 slides (P = 0.0001). TIS and routine screening were equivalent in sensitivity and specificity for the final cytology result, but BMSs were significantly more likely to classify slides as dyskaryotic rather than borderline when using TIS compared with routine screening. Referrals for potentially high‐grade abnormalities detected by TIS‐assisted IQC alone found 28 biopsies of at least cervical intraepithelial neoplasia grade 2 (CIN2+), whereas 15 CIN2+ biopsies were found on routine screening but missed using TIS. There was no significant change in the rates of inadequate tests, high‐ or low‐grade cytological abnormalities, or positive predictive value for CIN2+ when TIS was in use. Conclusions: Screening with TIS was more sensitive than RR for IQC, providing a rescreening method equivalent to routine primary screening in overall accuracy.     

Comparing the accuracy of ThinPrep Pap tests and conventional Papanicolaou smears on the basis of the histologic diagnosis: a clinical study of women with cervical abnormalities

OBJECTIVE: To confirm that the ThinPrep Pap test (TP) is as effective as or more effective than the conventional Papanicolaou smear (CS) in detecting epithelial cell abnormalities in a population with cervical abnormalities. STUDY DESIGN: In a blinded, split-sample, matched-pair study, a CS was prepared using a cytobrush, and then TP slides were prepared from the remainder of the sample. All slides were evaluated as defined and classified by the Bethesda System. The results of the two cytologic tests were compared in 483 women relative to the histologic diagnoses of subsequent colposcopically directed cervical biopsies in 158 cases. RESULTS: The cytologic diagnoses from the two methods agreed exactly in 91.4% of cases. The comparison between the two cytologic diagnoses with reference to the histologic diagnosis of subsequent colposcopically directed cervical biopsies showed that TP was significantly more specific for diagnosing lesions than was CS. The sensitivity of the two methods was equivalent. CONCLUSION: In a population with cervical abnormalities, TP is more specific than and as effective as CS in detecting cervical epithelial cell abnormalities. TP improved the specificity of disease detection by reducing the atypical squamous cells of undetermined significance category and/or false positive cases.     

100% rapid rescreening for quality assurance in a quality control program in a public health cytologic laboratory

OBJECTIVE: To verij5 the efficacy of the quality control (QC) program in a cytologic laboratwy with a rapid rescreening (RR) protocol. STUDY DESIGN: RR, according to the Turret RR method, of all samples initially screened as negative at the Laboratory of Cytology, Adolfo Lutz Institute, was performed. The slides were reviewed for 60 seconds. Suspect smears were fully checked by 2 reviewers to determine the final diagnoses. A total of 2954 sequential cytologic results were considered in this study. Of the 2954, 2568 (86.9%) were considered initially negative according to our internal QC, and these cases underwent RR. Also, 10% were randomly selected from these negative cases for full reviewing. The internal QC in our laboratory includes review of cases selected according to clinical and cytomorphologic criteria. RESULTS: Among the 2954 total cases, QC detected 386 (13%) atypias with final diagnoses reported according to The Bethesda System 2001 as follows: 82 (2.18%) low grade squamous intraepithelial lesions (LSILs), 35 (1.18%) high grade squamous intraepithelial lesions (HSILs), 2 (0.06%) squamous cell carcinomas, 105 (3.5%) atypical cells of undetermined significance (ASC-US), 4 (0.12%) atypical endocervical cells (AECs) and 158 (5.3%) unsatisfactory samples. RR of 2568 smears initially considered negative selected 194 (7.5%) slides. Of the 194, 146 (75.3%) were negative, 28 (14.4%) ASC-US, 5 (2.6%) AEC, 1 (0.5%) LSIL and 14 (7.2%) unsatisfactory. Full review of a 10% random fraction of the 2568 cases interpreted as negative did not detect lesions but did detect 5 (1.95%) unsatisfactory samples. CONCLUSION: Internal QC used in our laboratory based on clinical and cytomorphologic criteria to select cases for review proved to be an efficient method of detecting HSIL and cervical cancer. The consensus basis of this program strongly limits the false positive and false negative rates and also provides subjects with continuing education. One hundred percent RR is more efficient than 10% full reviewing in detecting cervical abnormalities.     

Atypical squamous cells of undetermined significance: audit and the impact of potential litigation. Retrospective review of 682 cases

For quality assurance purposes, the frequency of 'abnormal' cytological diagnoses of the non-systematic National Cervical Cancer Screening Programme (NCCSP) was evaluated. In 1999, an unexpected high number of Class (Cl) III cases (i.e. atypical squamous cells of undetermined significance) was reported. The cytological and histological results were reviewed in order to detect a possible cause for this threefold increase. The abnormal Papanicolaou (PAP) smears examined by conventional methods from 1 January 1990 to 31 December 2002 were analysed. The smears of 682 cases diagnosed in 1999 with a Cl III category were reviewed in 2000 and correlated with the available histological diagnoses provided by the Central Department of Pathology. Of the 682 Cl III cases, 176 cases (26.1%) had no follow-up, 314 cases (46.0%) had repeat cytology and 192 cases (28.2%) an histological correlate corresponding to 90 (46.9%) benign lesions, 78 (40.6%) squamous intraepithelial lesions, two (1%) invasive cervical cancers (one squamous and one glandular). Twenty-two Cl III cases (11.5%) were histologically within normal limits. Retrospective smear review confirmed 330 Cl III diagnoses (48.3%), 127 cases (18.6%) were recategorized as Cl IIIG (i.e. atypical glandular cells of undetermined significance), 22 cases (3.2%) as Cl IIID (i.e. mild to moderate dysplasia) and six cases (0.9%) as Cl IVa (i.e. severe dysplasia and/or carcinoma in situ). A total of 197 original Cl III cases had to be reclassified in the Cl II category (28.9%), only two cases showing mild and moderate dysplasia on histology. Thus, 195 cases (28.6%) comprised cytological overdiagnoses. The Cl III category being, by definition, a delicate and often subjective diagnosis, all external influences such as pressure of litigation should be avoided to reduce cytological overdiagnoses as a result of an unnecessary 'fear-factor'.     

Accuracy of thin-layer cytology in patients undergoing cervical cone biopsy

OBJECTIVE: To compare the accuracy of thin-layer cytology with Autocyte PREP (TriPath Imaging Inc., Burlington, North Carolina, U.S.A.) with conventional smears in 500 women undergoing cervical cone biopsy. STUDY DESIGN: The study was performed among 500 consecutive women presenting for cone biopsy for high grade cervical intraepithelial neoplasia (CIN) on biopsy in 350 (70%) and discrepant cytology/colpohistology in 150 (30%). Before performing a cone biopsy, two cervical samples were collected for conventional smears and thin-layer cytologic slides, with randomization of the order. Conventional smears were stained and diagnosed at Pasteur Cerba, while thin-layer cytologic slides were processed at a local TriPath office (Meylan, France) and sent in a masked fashion for screening at Pasteur Cerba. Any slides initially read as normal were reviewed again and reported without knowledge of the other cytologic or cone biopsy data. The final cytologic diagnoses for the two methods were compared with histopathology of the cone biopsy. RESULTS: The conventional smear was unsatisfactory in 58 (11.6%) of cases, while there were 4 (0.8%) unsatisfactory thin-layer cytologic slides (P < .001). Endocervical cells were missing from 31 (6.2%) of conventional smears and 34 (6.8%) of thin-layer cytologic slides. For the pooled data, sensitivities of conventional smear and thin layer for detecting high grade CIN (0.82% and 0.86%, respectively) were similar as were specificities (0.40% and 0.43%, respectively). When first samples were compared, the sensitivities of the conventional smear and thin layer for high grade CIN were 0.79% and 0.89%, respectively (P = .02), with corresponding specificities of 0.41% and 0.36% (P < .01). CONCLUSION: When controlled for sample order, the sensitivity of thin-layer cytology for detecting high grade CIN was significantly higher than that of conventional smears in patients with previous abnormal cytology, but at the expense of specificity.     

An Australian trial of ThinPrep: a new cytopreparatory technique

To evaluate the sensitivity and suitability of ThinPrep, a new slide preparation technique, 2026 paired cervical cytology slides were examined. After conventional Papanicolaou smears were prepared, the sampling instruments were rinsed in a fluid fixative. ThinPrep slides were then prepared in the laboratory from the surplus cells in the fixative. Compared with the Pap smears, ThinPrep slides were easier and quicker to screen, were inconclusive less often, and had similar rates for detecting abnormalities and infection. There were more unsatisfactory ThinPrep slides and more ThinPrep slides lacked endocervical cells. Both of these shortcomings were found to be linked to the choice of sampling implements. This study, in which a variety of sampling instruments was used, fails to confirm some of the previous claims made for the new technique.     

Liquid-based cytology can improve efficiency of cervical smear readers: evidence from timing surveys in two NHS cytology laboratories

OBJECTIVE: Cervical screening programmes in England and Wales were advised by the National Institute for Clinical Excellence in 2003 to adopt liquid-based cytology (LBC) in place of conventional Papanicolaou (Pap) cytology to facilitate laboratory efficiency. Pilot evaluations in England and Scotland monitored daily or weekly workloads of smear readers and concluded that LBC could increase hourly throughput rates. This study, instead, used timing surveys to determine screening rates. METHODS: Two National Health Service cytology laboratories in Manchester and Stockport were partially converted to the LBC ThinPrep process for a cervical screening trial. Three 1-week timing surveys were conducted over 7 months. The surveys covered all LBC-trained staff. The first survey in Manchester also covered staff undertaking conventional Pap screening. The smear readers used timers to record time taken for examining and reporting each slide. RESULTS: In Manchester, in the first survey, nearly 1 minute per slide was saved by the LBC method during primary microscopy. In both laboratories, the mean microscopy time for primary screening of LBC slides was reduced by almost 1 minute between the first and second surveys. There was no difference between the second and third surveys. Microscopy by cytopathologists was also 1 minute per slide quicker with LBC than conventional Pap. The LBC inadequate rates for both laboratories were <2.0%. Organizational factors impacted on the hourly LBC primary screening rates in the laboratories, the rate for Stockport being higher than the rates in the pilot evaluations. CONCLUSIONS: The timing surveys confirm that the LBC ThinPrep technology can improve laboratory efficiency. However, decision-makers should also consider the overall costs and benefits of introducing the technology in screening programmes, including the capital investment and workforce implications.     

Is it possible to define a better ASCUS class in cervicovaginal screening? A review of 187 cases

OBJECTIVE: To try to better define the cytologic diagnosis of atypical squamous cells of undetermined significance (ASCUS) in a cervical screening protocol. STUDY DESIGN: Smears from 187 patients with cytologic diagnoses of ASCUS and histologic or two years' cytologic/colposcopic follow-up were reviewed. When an ASCUS diagnosis was confirmed, it was done strictly on the basis of the morphologic criteria recommended by the Regione Emilia Romagna Screening Protocol in 1997, trying also to subclassify ASCUS into favor reactive or favor neoplasia. RESULTS: Seventy ASCUS cases were negative (37.4%). Three cases (1.6%) were low grade squamous intraepithelial lesion, and seven (3.8%) were high grade squamous intraepithelial lesion. One hundred seven ASCUS cases (57.2%) were confirmed. Among the 70 negative cases, 36 (51.4%) had reactive changes on biopsy, 30 (42.9%) koilocytosis, 3 cervical intraepithelial neoplasia (CIN 1) and one CIN not otherwise specified (5.7% total). CONCLUSION: Reclassification of ASCUS cases using tighter criteria reduced them to a rate of 57.2% but missed 30 patients with histologic diagnoses of koilocytosis and 4 with histologic diagnoses of CIN.     

Performance of monolayered cervical smears in a gynecology outpatient setting in Kuwait

OBJECTIVE: To compare ThinPrep (TP) Papanicolaou smears (Cytyc Corp., Box-borough, Massachusetts, U.S.A.) with matching conventional Papanicolaou (CP) smears for specimen adequacy, cytologic quality, diagnostic accuracy and screening time. STUDY DESIGN: In this prospective study of 1,024 women a split-sample, matched-pair design in favor of CP slides based on single-blind criteria was followed with a smear on a glass slide for CP and the remaining material collected in Preserv-Cyt solution (Cytyc) for a TP smear. A Cytobrush (Medscand, Hollywood, Florida, U.S.A.) was used for smear preparation for CP. TP smears were processed in ThinPrep 2000 (Cytyc). Smears were stained with Papanicolaou stain and were interpreted according to the Bethesda system. RESULTS: The number of satisfactory but limited (SBL) cases with TP were 77 (7.5%) as compared to 127 (12.4%) with the CP method. This reduction in SBL smears with the TP method and consequent increase in satisfactory smears were highly significant (P < .001) by McNemar's test. As regards unsatisfactory smears in discordant pairs, although the number of unsatisfactory smears was higher with TP (41 cases) as against CP (27 cases), the difference was not statistically significant (P < .05). The split-sample method showed a high correlation between the CP and TP diagnoses. TP smears had a significant advantage over CP smears in the reduction in the number of ASCUS and AGUS cases (14 vs. 29) (P < .05) and increased the pickup rate of LSIL, 6 vs. 1. Time taken to screen the TP smears was half that of CP smears. No cases of LSIL or HSIL were missed on TP smears. CONCLUSION: The liquid-based processor significantly improved the adequacy and quality of smears, resulting in fewer recall cases for SBL smears, leading to more definitive diagnoses in atypical cases, increasing the pickup rate of LSILs and reducing the screening time. A machine handling multiple specimens automatically would decrease cost and be an asset to a cytopathology laboratory.     

Cytohistologic correlation between AGUS and biopsy-detected lesions in postmenopausal women

OBJECTIVE: To evaluate histologic findings in patients aged 50 and older whose cervical smears revealed atypical glandular cells of undetermined significance (AGUS). STUDY DESIGN: Computerized records spanning a four-year period were retrospectively analyzed. Thirty patients over age 50 had cervical smears interpreted as AGUS and had follow-up biopsies within 12 months following the abnormal smear. The most important histologic diagnosis from the biopsy specimens was correlated with the subcategory of the cervical smear. RESULTS: Five smears interpreted as AGUS, favor reactive, revealed abnormal histology in four cases: three endometrial polyps and one squamous carcinoma. Two smears interpreted as AGUS, favor dysplasia, revealed squamous intraepithelial lesions on biopsy in both cases. Seventeen smears interpreted as AGUS, favor endometrial cells, revealed abnormal histology in 13 cases: 1 endocervical polyp, 6 endometrial polyps, 3 endometrial hyperplasias and 3 adenomyosis. Six patients with smears interpreted as AGUS, unclassifiable, revealed abnormal histology in five cases: two endocervical polyps, one endometrial polyp, one endometrial carcinoma and one ovarian carcinoma. CONCLUSION: The presence of AGUS in cervical smears from women over 50 was highly predictive of abnormal lesions detected by histologic examination. Although three cancers were detected on histologic follow-up, the most common lesions detected were endometrial polyps.     

Expert consultation for cervical carcinoma smears. Reliability of selected-field videomicroscopy

OBJECTIVE: To evaluate the diagnostic accuracy of videomicroscopy image selection for expert consultation in cervical cytology. STUDY DESIGN: One hundred diagnostically difficult cervical cytologic smears were selected and rescreened by a general pathologist who chose, from each slide, four or five fields featuring abnormal cells. Video images were digitized and stored on a 512 x 512-pixel matrix using an image acquisition and transmission system. Five experts each reviewed 20 of the 100 cases, and a sixth reviewed all 100 cases. Diagnoses based on selected digitized images were compared to those based on conventional examination of whole slides. RESULTS: Intraobserver agreement was fair to excellent for all six experts (kappa value: 0.47-0.81); it was complete or acceptable in 68.4-85% of cases. Compared to the reference diagnosis, interobserver agreement was not significantly different whether cases were examined by screening the entire slide or by videomicroscopy of selected fields. The marked discordance in four cases concerned very small cells the significance of which was misinterpreted on videomicroscopy because of poor image quality due to lack of focus setting. CONCLUSION: This exploratory study showed that selection of videomicroscopy images seems as reliable as conventional examination of slides for expert consultation on diagnostically difficult cervical cytologic smear cases.     

False negative rate of cervical cytologic smear screening as determined by rapid rescreening.

OBJECTIVE: To determine the reliability of the false negative rate (FNR) of cervical cytologic smear screening by rapid rescreening. STUDY DESIGN: A test set of 401 cases (311 originally diagnosed as negative, 74 as atypical squamous cells of undetermined significance [ASCUS], 14 as low grade squamous intraepithelial lesion [LSIL] and 2 as high grade squamous intraepithelial lesion [HSIL]) were rapidly (30 seconds each) rescreened by five cytotechnologists with no prior experience in rapid rescreening, and the FNRs of rapid rescreening and primary screening were determined. These results were compared with each other and with the FNR of primary screening as determined by routine rescreening of all cases with no time limit. RESULTS: All five observers detected a different group of abnormal cases; only 9% of all cases originally diagnosed as ASCUS or worse and 43% of all cases diagnosed as LSIL or worse were detected by all five observers. Nevertheless, using ASCUS as the threshold for an abnormal result, the FNR of rapid rescreening fell into a relatively narrow range, 61-74% (mean, 68.2 +/- 5.0); using LSIL as the threshold resulted in FNRs of rapid rescreening between 25% and 38% (30.0 +/- 4.7). Each observer, using rapid rescreening, detected between one and three false negative cases; routine rescreening of all cases without a time limit detected five cases. The FNR of cervical cytologic smear screening, as determined by rapid rescreening, was 18.4 +/- 6.1% as compared with 14.8% by routine rescreening without a time limit. CONCLUSION: The FNR of rapid rescreening is relatively reproducible even though the individual cases identified varied between reviewers. The FNR of rapid rescreening is similar to that of routine rescreening. Rapid prescreening may be the most logistically simple method to determine the true FNR of a laboratory.     

Sensitivity of HPV tests on stained vs. unstained cervical smears

OBJECTIVE: To examine the effect of Pspanicolaou staining of cervical smears on the sensitivity of molecular biologic HPV tests. STUDY DESIGN: Two sensitive HPV tests were used, HPV DNA sequence analysis after polymerase chain reaction (PCR) amplification and the Hybrid Capture II method (HC II) (Digene Diagnostics Inc., Silver Spring, Maryland, USA). Papanicolaou-stained and unstained smears taken simultaneously were examined from 265 women readmitted for examination due to an atypical squamous cells of undetermined significance diagnosis. RESULTS: After an HPV test with the PCR method on unstained slides, 66% of the women were HPV positive, whereas the same women were HPVpositive in 54% when Papanicolaou-stained slides were analyzed. However, this difference was not statistically significant (p > 0.1). With the HC II method, 55% of unstained smears were HPV positive whereas 29% were HPV positive, when Papanicolaou-stained slides were examined. This difference was significant (p < 0.001). The same strong differences in sensitivity were observed when both the PCR and HC II methods were studied on the same Papanicolaou stained glass slides, whereas on unstained slides no significant difference was found. CONCLUSION: The results demonstrate that Papanicolaou staining of a cervical smear significantly decreases the sensitivity of an HPV test performed with the HC II method, whereas the PCR method is less affected. With the Papanicolaou method, the hematoxylin bath is followed by HCl treatment, and strong acid treatment destroys DNA.