Subclassifying atypical squamous cells in Thin-Prep cervical cytology correlates with detection of high-risk human papillomavirus DNA

Interobserver agreement in the interpretation of anal cytology

BACKGROUND

Anal cytology represents a tool for anal cancer screening in high-risk populations. In addition to accuracy, the reproducibility of the interpretation is of key importance. The authors evaluated the agreement of anal cytologic interpretation between two cytopathologists.

METHODS

Liquid-based cytologic slides from human immunodeficiency virus (HIV)-negative men who have sex with men (MSM) were evaluated by two readers with at least 10 years of expertise in cervical cytology. Cases with a discordant interpretation were reviewed, and a consensus was reached. Human papillomavirus (HPV) genotyping was performed using a proprietary HPV genotyping test. Unweighted and weighted Cohen kappa and 95% confidence interval (CI) values were calculated.

RESULTS

Overall, 713 slides that were adequate for interpretation were evaluated (MSM: median age, 33 years). An HPV test was performed on 620 samples (87.0%). Considering a dichotomous interpretation (negative for intraepithelial lesion or malignancy vs. atypical squamous cells of undetermined significance or worse), the crude agreement between the two readers was 93.3% (kappa = 0.82; 95% CI, 0.77-0.87). Once a consensus for discordant cases was reached, the best agreement was found for the negative for intraepithelial lesion or malignancy category (511 of 528 samples; 96.8%), whereas the atypical squamous cells of undetermined significance category showed the lowest agreement (90 of 117 samples, 76.9%). Considering the individual cytologic categories, overall agreement was 92.1% (kappa = 0.85; 95% CI, 0.81-0.89). The discordant interpretations were not associated with high-risk HPV infection, HPV16 infection, or MSM age.

CONCLUSIONS

The results indicating excellent interobserver agreement in this study substantiate the use of anal cytology in the setting of human immunodeficiency virus-negative MSM.

Inter- and intraobserver agreement in whole-slide digital ThinPrep samples of low-grade squamous lesions of the cervix uteri with known high-risk HPV status: A multicentric international study

BACKGROUND

High-risk human papilloma virus (HR HPV) testing and liquid-based cytology are used for primary cervical screening. Digital cytology, based on whole-slide scanned samples, is a promising technique for teaching and diagnostic purposes. The aim of our study was to evaluate the interobserver and intraobserver variation in low-grade squamous lesions, HR HPV status bias, and the use of whole-slide scanned digital cervical cytology slides.

METHODS

Fifteen expert cytopathologists evaluated 71 digitalized ThinPrep slides (31 atypical squamous cells of undetermined significance [ASC-US], 21 negative for intraepithelial lesion or malignancy, and 19 low-grade squamous intraepithelial lesion cases). HR HPV data were accessible only in the second round.

RESULTS

In interobserver analysis, Kendall's coefficient of concordance was 0.52 in the first round and 0.58 in the second round. Fleiss' kappa values were 0.29 in the first round and 0.31 in the second round. In the ASC-US category, Fleiss kappa increased from 0.19 to 0.22 in the second round and the increase was even higher expressed by Kendall's coefficient: from 0.42 to 0.52. In intraobserver analysis, personal scores were higher in the second round.

CONCLUSIONS

The interobserver and intraobserver variability in low-grade squamous lesions was within fair agreement values in the present study, in line with previous works. The comparison of two rounds showed that expert cytopathologists are generally unbiased by the knowledge of HR HPV data, but that being informed of the HR HPV status leads to a better agreement. Stain quality and back discomfort were highlighted as factors affecting digital cytopathology use.

What is atypia? Use, misuse and overuse of the term atypia in diagnostic cytopathology

The term "atypical" was introduced by the founder of modern cytodiagnosis, Dr. George N. Papanicolaou, to convey a very low suspicion of (pre)malignancy. Despite controversies concerning its ambiguous and imprecise definition and its uncertain optimal use, the term "atypia" has continued to be used in cytopathology, and has recently been increasingly used in standardized nongynecologic cytopathology diagnostic reporting terminologies. Its increasing use suggests that "atypia" continues to be a useful category to fill the gap between what we can recognize as entirely normal (including reactive changes) and what we can recognize as clearly abnormal (premalignant or malignant). However, this diagnosis should be used parsimoniously, since the potential overuse of "atypia" diagnoses can lead to the erosion of clinicians' confidence in cytopathology, their misunderstanding of the cytopathology report, and to an increase the clinicians' diagnostic uncertainty, with negative consequences on patients' satisfaction and wellbeing, and on health care costs. A clinically meaningful, standardized cytodiagnostic category of "atypia" requires a narrow definition, quantitative criteria, agreed-upon reference images, a clear clinical meaning (likelihood of underlying malignancy or premalignancy) and, ideally, well-defined management options. The successful implementation of such a standardized "atypia" diagnostic category requires continuous education of cytology professionals and quality assurance efforts to monitor its use. The interobserver variability and potential excessive use of the diagnosis of "atypia" may be reduced by considering and addressing the major factors involved in its variable use, namely the quality of the sample, the definition of "atypia", the education/training of the cytologist/pathologist, and cytologist/pathologist-related "supracytologic" factors.

Interobserver variability of cervical cytology in HIV-infected women

OBJECTIVES

Our objectives were to determine the reproducibility of cytological specimen interpretation between two pathologists in human immunodeficiency virus (HIV)-infected women (from the VIHGY, ANRS CO17 study of human papillomavirus genital pathology among HIV-positive women) and to analyse the improvement, if any, between conventional and liquid-based cytology (LBC) interpretations.

MATERIALS AND METHODS

A sample of all abnormal and 40% of randomly selected normal Papanicolaou (Pap) tests was randomly ordered and read blindly by a second pathologist using the revised Bethesda terminology 2001. For both conventional and liquid-based preparations, unweighted and Cicchetti-Allison-weighted kappa and their 95% confidence intervals (CIs) were calculated. Kappa values were then compared using the Altman rule to classify the reproducibility of cytological specimen interpretation.

RESULTS

Two hundred and seventy-seven conventional Pap tests were reviewed, including 79 abnormal and 10 unsatisfactory results. Overall agreement between the two observers was 78%, with an estimated Cicchetti-Allison-weighted kappa of 0.69 (95%CI, 0.61-0.77). The corresponding values for the 268 LBCs, including 123 abnormal and two unsatisfactory results, were 84% and 0.82 (95%CI, 0.76-0.87), respectively. The reproducibility of LBC interpretations was significantly higher than that of conventional preparations (P = 0.009) and, for both laboratories, the percentages of unsatisfactory results were significantly lower for LBC.

CONCLUSION

In HIV-infected women in the combination antiretroviral therapy era, the strength of agreement was better for LBCs than for conventional preparations, with a lower percentage of unsatisfactory results. When available, LBC should be preferred because of its higher reproducibility.

Comparison of diagnostic cytomorphology of atypical squamous cells in liquid-based preparations and conventional smears

Background

The aims of this study were to compare the cytomorphologic features diagnostic of atypical squamous cells (ASC) in liquid-based preparations (LBPs) and conventional Pap (CP) smears and to cytomorphologically assess the performance of the Cell Scan 1500™ in cervical cytology practice.

Methods

Cervicovaginal smears were obtained from 938 women. Two smears were obtained simultaneously from each individual, one for an LBP and the other for a CP smear; the smears were independently examined. ASC was diagnosed in 24 patients, and their samples were cytomorphologically and semiquantitatively analyzed.

Results

A total of 24 of the 938 women (2.6%) were diagnosed with ASC by one or both methods. Results from LBPs and CP smears were in agreement in 13 of 24 cases of ASC diagnosis (absolute direct agreement, 54.2%; k<0.20; p-value from chi-square test=0.085). Diagnostic features of ASC in the LBPs included squamous cell atypia and atypical squamous metaplasia.

Conclusions

The cellular features diagnostic of ASC present in one preparation can manifest themselves differently in the other. Changes in individual cells, particularly nuclear changes, are the most reliable features for diagnosing ASC. The Cell Scan 1500™ processor is more effective at detecting ASC than are CP smears.

Liquid-based cytology in diagnosing nasopharyngeal carcinoma

BACKGROUND

Liquid-based cytology (LBC) has achieved great success in cytological diagnosis of various cancers when compared with conventional smear methods. However, its application in diagnosing nasopharyngeal carcinoma (NPC) has never been studied.

METHODS

Eighty-four consecutive patients who underwent nasopharyngeal biopsy for suspicious NPC or a nasopharyngeal mass under nasopharyngoscopy were enrolled in this prospective study. Brush samples were taken from the same site before punch biopsy and processed with the Thin Prep test.

RESULTS

The adequacy, accuracy, sensitivity, specificity, false-negative rate, and false-positive rate of LBC in diagnosing NPC were 92.9% (78 of 84), 93.6% (73 of 78), 84.2% (16 of 19), 96.6% (57 of 59), 15.8% (three of 19), and 3.4% (two of 25), respectively. There were four inadequate specimens from patients with NPC and two inadequate ones from those without NPC.

CONCLUSIONS

Our study showed that the adequacy, accuracy, sensitivity, specificity, and diagnostic rate of LBC were equivalent to those using conventional smear methods. Although the diagnostic rate of NPC was lower using brush cytology than by punch biopsy, further improvements in the sampling technique could make brushing cytology a potential tool for NPC screening.

Human papillomavirus (HPV) in atypical squamous cervical cytology: the Invader HPV test as a new screening assay

In surveillance for cervical neoplasia, a diagnosis of cytologically atypical squamous cells of undetermined significance (ASCUS) presents a significant clinical issue, often dependent on testing for high-risk (HR) human papillomavirus (HPV) for the triage of patients. HPV type 16 now appears to be a critical concern in the follow-up of patients with ASCUS. The Invader HPV (Inv2) test, by Third Wave Technologies, Inc., is a recently developed analyte-specific reagent assay that uses probe sets for the detection of 14 HR HPV subtypes. These probe sets are A5/A6 (HPV types 51, 56, and 66), A7 (HPV types 18, 39, 45, 59, and 68), and A9 (HPV types 16, 31, 33, 35, 52, and 58). This report describes the performance characteristics of the Inv2 test in the screening of ASCUS cervical cytology specimens and correlates the results of the Inv2 test with those of the Hybrid Capture II HPV (HC2) test by Digene. The linear array HPV genotyping test (Roche Molecular Systems) was used as a reference method for the testing of samples with discordant results. Ninety-four Pap smear samples with a cytological diagnosis of ASCUS and 39 samples with a negative diagnosis were tested. The results of the Inv2 test demonstrated a good (86.6%) concordance with those of the HC2 test, with an overall sensitivity and specificity of 96% for the Inv2 test. Additionally, the Inv2 assay, which offers high-throughput, semiautomated DNA extraction, allows the subgrouping of HPV types by differential probe sets, could provide a useful test for screening for HPV, and has the potential to provide an improved means of risk stratification and the selection of patients for further HPV subtyping.

Atypical squamous cells-cannot exclude high-grade squamous intraepithelial lesion (ASC-H): a result not to be ignored

OBJECTIVE

The objective of this study was to determine the risk of a clinically significant lesion associated with the diagnosis of atypical squamous cells-cannot exclude high-grade squamous intraepithelial lesion (ASC-H) on cervical cytology (Pap smear).

METHODS

This was a retrospective, observational, descriptive study. A computerized database containing cytologic and histologic information for the health region was used to identify women with a diagnosis of ASC-H on a Pap smear performed between January 1 and December 31, 2002. All pertinent pathology data (cytopathology, histopathology, and surgical specimens) were examined. Patients were excluded if they had a diagnosis of cervical cancer, adenocarcinoma in situ (AIS), or high-grade squamous intraepithelial lesion (HSIL) prior to the index Pap smear.

RESULTS

During the study period, 727 of 241 841 Pap smears (0.3%) were reported as ASC-H in 655 patients. Ninety-one patients had a previous diagnosis of cervical cancer, AIS, or HSIL and were excluded from analysis, and 12 patients on review did not have ASC-H. There were no follow-up data for 35 of the remaining 552 patients, leaving 517 patients in the study group. In this group, the rates of histologically proven cervical lesions were 2.9% (15/517) for cervical cancer, 1.7% (9/517) for AIS, and 65.6% (339/517) for HSIL. Women undergoing a procedure that included histological examination were more likely to have a significant lesion discovered.

CONCLUSION

The diagnosis of ASC-H on Pap smear is associated with an appreciable risk of clinically significant disease. Patients with an ASC-H Pap smear result should undergo timely colposcopic and histologic assessment to rule out HSIL, AIS, and cervical cancer.

Human papillomavirus testing and molecular markers of cervical dysplasia and carcinoma

Cervical cancer is the second most common cancer in women worldwide. Human papillomavirus (HPV) is the etiologic agent for the vast majority of premalignant and malignant lesions, and high-risk HPV types can be detected in almost all cases of cervical dysplasia and carcinoma. HPV testing has been widely adopted for the triage of patients after a cervical cytology screening test (Papanicolaou smear or liquid-based cervical cytology such as ThinPrep or SurePath) interpretation of atypical squamous cells of undetermined significance (ASCUS), and HPV testing is increasingly used for screening in conjunction with cervical cytology. Although cervical cytology is a highly effective screening test for cancer, it has limited specificity for clinically significant lesions in cases with low-grade cytologic abnormalities. Up to a quarter of all patients may have a false-negative result on the basis of cervical cytology testing alone. This review focuses on HPV testing methods and molecular markers and their clinical relevance. HPV testing and surrogate molecular markers of HPV infection (p16INK4a) may help identify cases that are associated with underlying high-grade premalignant or malignant lesions and may also reduce aggressive treatment of patients with low-grade lesions.

Analyses of atypical squamous cells refined by the 2001 Bethesda System: the distribution and clinical significance of follow-up management

This study was conducted to analyze the clinical significance of follow-up diagnostic methods of atypical squamous cells (ASC) (the 2001 Bethesda System) cases according to age. A computerized search of the cytology database was performed to retrieve all cases diagnosed as ASC from 2001 to 2003. The pathologic reports for all follow-up diagnoses were reviewed. We divided the patients into two groups according to their age, younger than 50 years of age and 50 years and older, and follow-up diagnoses were compared between the two groups. ASC was identified in 1035 (2.0%) of 49,882 women screened, and a total of 914 patients were eligible. In atypical squamous cells of undetermined significance (ASC-US) cases, colposcopically directed biopsy showed CIN I (CIN is cervical intraepithelial neoplasia) or higher grade lesions in 34.9% of cases younger than 50 years of age and in 17.4% of cases 50 years and older (P= 0.000). However, repeat Pap smears and human papillomavirus DNA testing showed no differences between the two groups. In contrast, the three methods did not exhibit significant difference between the two groups in patients with atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H) (P= 0.743). Colposcopically directed biopsy for the ASC-US was more useful in patients younger than 50 years of age than in those who were 50 years and older. It is suggested that age should be considered in deciding follow-up diagnostic methods in patients with ASC-US.

Atypical squamous cells of undetermined significance-favour reactive compared to atypical squamous cells of undetermined significance-favour dysplasia: association with cervical intraepithelial lesions and human papillomavirus infection

BACKGROUND AND OBJECTIVES

The current study compared the cervical cytological sub-category "atypical squamous cells of undetermined significance-favour reactive (AFR)", recently recommended to be eliminated by the Bethesda system, to the sub-category "atypical squamous cells of undetermined significance-favour dysplasia (ASC-US)", in terms of prevalence of coexistent squamous intraepithelial lesions of either low-grade (LSIL) or high-grade (HSIL) and rate of human papillomavirus (HPV) infection.

STUDY DESIGN

One hundred women with AFR and 100 with ASC-US were consecutively included in the study. All patients underwent colposcopy, followed by biopsy when necessary, and were screened for HPV infection by the combined use of Hybrid Capture II (DIGENE) and PCR with MY09/11 primers, the latter followed by direct sequencing of the amplifications products for HPV genotyping.

RESULTS

LSIL were detected in 5.6% of AFR and 18.5% of ASC-US (p=0.00812), HSIL only in 4.3% of ASC-US. HPV infection was diagnosed in 11.2% of AFR and 38.0% of ASC-US (p=0.00003); high-risk HPV types (namely, HPV-16, -18, -31, -66, -67 and -70) were found in 6.7% of AFR and 22.8% of ASC-US (p=0.00239). Evidence of HPV infection in absence of SIL was proven in 7.1% of AFR and in 22.5% of ASC-US (p=0.00622).

CONCLUSION

The association of AFR with SIL and high-risk HPV infection is low but not inexistent. Thus, to avoid the risk of leaving some high-risk AFR patients untreated or without follow-up, it could be proposed to keep AFR as a cytological category and to triage it by HPV testing, similarly to what has been already recommended for ASC-US.

Effect of Bethesda 2001 on reporting of atypical squamous cells (ASC) with special emphasis on atypical squamous cells-cannot rule out high grade (ASC-H)

We compared the overall ASC rate and the outcomes for women with different categories of ASC before and after TBS 2001 to evaluate the impact of TBS 2001. Our laboratory reported ASC in four subcategories before TBS 2001; ASC, favor reactive (ASC-R), favor low-grade squamous intraepithelial lesion (SIL) (ASC-L), undetermined significance (ASC-US), and ASC-H. Since the implementation of TBS 2001, we have been reporting ASC as ASC-US and ASC-H. After TBS 2001, our ASC rate decreased from 6.2% to 4% (P < 0.0001). Before TBS 2001, ASC-R carried the same risk as ASC-US for underlying condyloma/CIN 1. Moreover, ASC-R was rarely associated with CIN 2 or 3. Before TBS 2001, ASC-H captured more low-grade (condyloma/CIN 1) and less high-grade (CIN 2, 3, and SCC) lesions compared to after TBS 2001. More women with ASC-H after TBS 2001 underwent colposcopy (80% vs. 71%, P < 0.05). Twenty-two percent of women with ASC-H required 2-4 colposcopies to identify the high-grade lesion. Our results confirm that consistent application of TBS 2001 terminology for ASC reduces the ASC rate, and better identifies women at high risk for CIN 2, 3, and SCC. In addition, ASC-H requires very close clinical follow-up as a significant percentage of women require more than one colposcopy to identify the high-grade lesion.

A comparison of modified MonoPrep2™ of liquid-based cytology with ThinPrep® Pap test

OBJECTIVE

The purpose of this study is to evaluate a modified MonoPrep2 (MP) of liquid-based cytology (LBC) to search for a less expensive alternative technique usable for screening of cervical cancers.

STUDY DESIGN

Cervicovaginal direct-to-vial samples from 1218 consecutive patients were processed with the modified MP technique and the results were compared with those of currently popular ThinPrep Pap test (TP) technique.

RESULTS

Both MP and TP methods provide uniformly spread thin layers of cells without cellular overlap or significant obscuring elements. The diameter of the circular area was 20 mm in MP and 22 mm in TP. Obscuring factors were slightly more frequent in MP but not enough to affect interpretation. Thirteen specimens were excluded from the study because of poor specimen quality in MP. In 1205 patients, there was an absolute agreement in results (the Bethesda diagnosis system) between the two methods, and discordances were observed in only 18 (1.5%) in 1187 cases (98.5%). Furthermore, there was no significant difference in diagnostic accuracy in histopathologic correlation between the two methods. The sensitivity of MP was slightly lower than that of TP, and the specificity of MP was higher than that of TP. A human papillomavirus (HPV) test with polymerase chain reaction (PCR) using broad-spectrum probes has yielded good results in both MP and TP samples.

CONCLUSIONS

The modification of the MP method gave comparable results to those of TP in terms of smear quality, cytologic diagnostic evaluation, and biopsy correlation with much less cost. The modified MP offers a cost-effective alternative to the currently popular expensive techniques of liquid-based cytology practical for cervical cancer screening.

Pap test in a high-risk population comparison of conventional and liquid-base cytology

Liquid-based cytology (LBC) is believed to have better sensitivity than conventional smears (CSs) and offers the possibility to perform molecular assay. The goal of this work was to study the performance of CS and LBC in a high-risk population and to compare the results with the hybrid capture (HC) II for high-risk human papillomavirus (HPV). Samples were collected from selected women with clinical suspicions of low genital tract lesion at Pérola Biygnton Hospital (São Paulo, Brazil). After CS preparation, the brush was introduced in the endocervix and a new sample was collected and rinsed in the preservative medium of the system. The residual material was used to HC2. From 925 cases, LBC was unsatisfactory in 4 (1.51%) cases and CS was unsatisfactory in 100 cases (10.81%); among theses cases HC2(+) reactions was observed in 54 (54%) CSs and 3 (21.4%) LBCs. Considering cases with atypia of undetermined significance (squamous and glandular), 85 (77.27%) cases from LBC and 44 (86.4%) from CS were positive for HC2 assay for high-risk DNA-HPV. The difference among the methods was not significant (P < 0.38). The diagnosis improvement of LBC in comparison with CS was 86% in satisfactory samples, 92.76% in undetermined atypical lesions (including glandular), 83% in positive low-grade squamous intraepithelial lesions (LSIL(+)), and 86.84% in high-grade SIL(+) (HSIL(+)). HC2(+) reactions were observed in 144 CS cases and 266 LBC cases with abnormalities. Our results have showed that LBC was superior to CS in a high-risk population to detect lesions with high concordance with HC2(+) reactions; CSs also exhibit a high concordance with HC2 assay but with inferior performance to detect lesions.

Human papillomavirus oncogenic expression in the dysplastic portio; an investigation of biopsies from 190 cervical cones

In this study, we investigated the presence of E6/E7 transcripts of seven common high-risk human papillomavirus (HPV) types in 190 cervical biopsies. The RNA-based real-time nucleic acid sequence-based amplification assay (NASBA) and type-specific PCR, both detecting HPV 16, 18, 31, 33, 45, 52, and 58, as well as consensus PCR, were performed on all 190 biopsies. High accordance between type-specific and consensus PCR confirms that the HPV types included in this study are the most common types present in cervical dysplasia. Furthermore, we see a clear increase in the incidence of HPV, both DNA and RNA, along with the histological severity of dysplasia. HPV RNA was detected in all but two PCR-positive cases, confirming that the virus exerts E6/E7 mRNA expression in cases of high-grade dysplasia. Out of 19 women given a normal or borderline diagnosis at conisation, only four were found HPV positive, which may suggest that unnecessary conisations can possibly be reduced by introducing HPV testing into the preoperative routine assessment.

Comparison of Human Papillomavirus DNA Prevalence in Atypical Squamous Cells of Undetermined Significance Subcategories as Defined by the Original Bethesda 1991 and the New Bethesda 2001 Systems

Context.—The new Bethesda System 2001 (TBS 2001) minimized the subclassification of atypical squamous cells of undetermined significance (ASCUS).

Objective.—The primary goal of this study was to determine the impact of the new subclassification on the accuracy of Papanicolaou (Pap) test diagnosis by examining the prevalence of human papillomavirus (HPV) DNA in different ASCUS subcategories, as defined by the new TBS 2001 versus the original TBS 1991. The second goal was to identify specific morphologic features of atypical squamous cells that are more frequently associated with HPV detection.

Design.—Consecutive cases of ThinPrep Pap tests were retrospectively reviewed by a panel of pathologists to obtain consensus diagnoses. The study group consisted of ASCUS cases; the positive control group consisted of low- and high-grade squamous intraepithelial lesions (LSILs and HSILs, respectively); and the negative control group consisted of cases “negative for intraepithelial lesion or malignancy.” All ASCUS cases were subclassified according to TBS 1991 into the following categories: favor reactive (ASCUS-R), favor LSIL (ASCUS-L), favor HSIL (ASCUS-H), and not otherwise specified (ASCUS-NOS). In a separate review, ASCUS cases were subclassified according to TBS 2001 into the following categories: atypical squamous cells of undetermined significance (ASC-US) and atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H). Furthermore, morphologic ASCUS subtypes were recorded (atypical mature, immature, parakeratotic, and atrophic cells); in addition, individual morphologic features of atypical cells were recorded. Broad- spectrum HPV DNA amplification and genotyping was performed using short PCR fragment (SPF 10) polymerase chain reaction/Line Probe assays.

Results.—In cases classified according to TBS 1991, HPV was detected in 32% of negative, 49% of ASCUS, and 93% of LSIL/HSIL cases. On the second review, using the diagnostic categories of TBS 2001, which eliminated the ASCUS-;R category, the number of ASCUS cases decreased by 45%. The prevalence of HPV DNA in ASCUS cases downgraded to the negative category was 38%, which was not significantly different from HPV prevalence in negative cases as diagnosed under TBS 1991. Furthermore, HPV was detected in 56% of ASC-US and 71% of ASC-H cases. The prevalence of HPV in different morphologic subtypes of ASCUS was not significantly different, and none of the 8 individual morphologic features of atypical cells were more frequently associated with HPV detection.

Conclusion.—Elimination of the ASCUS-R category in TBS 2001 resulted in a significant decrease in the number of ASCUS diagnoses. Downgraded cases had a relatively low prevalence of HPV DNA. It is expected that TBS 2001 will increase specificity of the Pap test without compromising its sensitivity.

Atypical squamous cells of undetermined significance on cervical smears

BACKGROUND

The current study reports on the significance of cervical smears identified as atypical squamous cells of undetermined significance (ASCUS) in the largest Asian screening population to date.

METHODS

From January 1998 to December 1999, 190,000 cervical smears were evaluated by the cervical cytology laboratory at the University of Hong Kong (Hong Kong, China). From these smears, 5579 ASCUS were identified. Follow-up cytology and histology findings were analyzed.

RESULTS

Follow-up cytology or biopsy results were retrieved for 3601 women (64.5%). Of these, 544 (9.8%) and 96 women (1.7%) were found to have low-grade (LSIL) and high-grade (HSIL) squamous intraepithelial lesions, respectively. Biopsy results were obtained for 198 (36.4%) of the 544 women with LSIL. One hundred seventy-nine (32.9%) and 19 women (3.5%) were confirmed to have cervical intraepithelial neoplasia (CIN)-1 and CIN-2-CIN-3, respectively. Biopsy results were retrieved for 53 (55.2%) women with HSIL. Forty patients (41.7%) were confirmed to have CIN-2-CIN-3, whereas CIN-1 was found in the remaining patients. One woman with squamous cell carcinoma was diagnosed by colposcopic biopsy after immediate referral following a diagnosis of ASCUS. There was a significantly larger proportion of LSIL or HSIL (P < 0.0001) or higher-grade findings in women with ASCUS compared with the general screening population. Infective organisms were identified in 412 women (7.4%) with ASCUS. These women had a decreased risk of subsequent development of LSIL (P < 0.0001) or HSIL (P = 0.027).

CONCLUSIONS

ASCUS smears indicated an increased risk of HSIL or carcinoma. The authors suggested careful patient follow-up in such cases.

Atypical squamous cells: update on current concepts

Besides all the confusion and associated problems that the use of ASC has created, it has initiated substantial investigational interest that has resulted in a better understanding of squamous intraepithelial lesions and the biology of cervical neoplasia. Although the category of ASC has created, and will continue to create, controversy in the diagnostic and management fields, it allows the pathologist to convey uncertainty that may be the result of poor sampling or difficulty in interpretation of a case. It is a valuable tool that the cytopathologist can use to make it known that the Papanicolaou test has its limitations and may need and benefit, in some instances, from support from ancillary studies. Similar limitations are recognized in other areas of pathology and the use of immunohistochemistry or molecular studies is widely accepted as an aid to a more specific and definitive interpretation. The time for the Papanicolaou test to be considered similarly has arrived. HPV DNA testing may not be the perfect test for cervical cancer screening because of high prevalence of HPV infection in the general population; however, it is currently the best-studied ancillary test and has been proven to be cost-effective for the triage of Papanicolaou tests with equivocal squamous cells. It is important for the cytopathologist to have well-developed diagnostic skills in interpreting gynecologic preparations, and to classify cases as ASC only when deemed appropriate. Downgrading cytologic findings that are diagnostic of a squamous intraepithelial lesion to ASC with the hope of supporting it by an HPV test will only result in a devaluation of the Papanicolaou test. Such recourse may, however, be acceptable in specific situations, such as in patients who have complex histories, atypical clinical presentations, or during pregnancy. Quality assurance measures to closely monitor the ASC:SIL ratio and the rate of HPV positivity in ASC cases will be essential to ensure the appropriate use of this interpretive category. The coordination of the 2001 Bethesda and ASCCP consensus meetings resulted in the new subcategories of ASC-US and ASC-H, along with well-defined management strategies for these interpretations. This new and clinically relevant terminology should lead to a reduction in difficulties at the clinical level and a more uniform management of patients, unlike the situation following Bethesda 1991 where the gynecologist was faced with a new "diagnosis" without specific management recommendations. The standardization of reporting and clinical management will also allow more reliable evaluation of patient outcomes and cost analysis. The 2002 American Cancer Society guidelines did not make specific recommendations regarding HPV DNA testing for the triage of patients who have a cytology result of ASC-US [64]. The FDA approved the expanded use of HPV testing in conjunction with the Papanicolaou test for cervical cancer screening in March of 2003. The future is likely to bring additional testing modalities that may be more specific for detecting squamous lesions that are more likely to persist or progress to carcinoma, than the currently available HPV tests. In addition, looking to the more distant future, recently published data from HPV vaccine trials suggests that immunizing women who are negative for HPV-16 may eventually reduce the incidence of cervical cancer [65]. At the present, however, the most effective method to decrease the mortality of this disease process is to make sure that all women have access to, and receive, effective cervical cytologic screening.

Reporting of atypical squamous cells, cannot exclude a high-grade squamous intraepithelial lesion (ASC-H) on cervical samples: is it significant?

"Atypical squamous cells, cannot exclude a high-grade squamous intraepithelial lesion (ASC-H)" is a new diagnostic category in the 2001 Bethesda nomenclature system for cervical cytology. The purpose of this 7-mo retrospective study (March 1, 2002-September 30, 2002) was to evaluate the significance of ASC-H on cervical Thin Prep Pap Tests. During this period, 25 (0.27%) of 9,214 Pap Tests were diagnosed as ASC-H, 22 of which resulted in either follow-up cervical biopsies and/or cervical cones, and which formed the basis of this study. Tissue specimens (22 cases) were negative in 5 cases (23%) and positive in 17 cases (77%). Of the positive specimens, there were 2 (12%) low-grade squamous intraepithelial lesions (LSIL) and 15 (88%) high-grade squamous intraepithelial lesions (HSIL). Of the 22 cases, ASC-H diagnoses included immature/atypical squamous metaplasia vs. a squamous intraepithelial lesion (SIL) in 19 (86%) cases, and tight clusters of small cells with a high nuclear to cytoplasmic ratio in 3 (14%) cases. The results of this study indicate that the reporting of ASC-H on cervical samples does lead to the detection of HSILs in a significant number of cases (68% in this study). Therefore, further evaluation of the patient is warranted.

Papanicolaou tests and molecular analyses using new fluid-based specimen collection technology in 3000 Japanese women

A fluid-based Papanicolaou test has been established to improve sample collection and preparation. This study was the first large-scale investigation in Japan to examine the feasibility of using fluid-based Papanicolaou specimens to detect human papillomavirus (HPV) using Hybrid Capture II and polymerase chain reaction (PCR). Three thousand patients who visited Keio University Hospital between October 2000 and February 2001 were enrolled in the study. The results of the fluid-based Papanicolaou tests corresponded well with those of conventional Papanicolaou smears (96.8% concordance). The sensitivities of cervical neoplasia detection using the fluid-based Papanicolaou test (73.9%) and Hybrid Capture II (76.3%, P=0.55) were not significantly different. Among the cervical intraepithelial neoplasia 3 and squamous cell carcinoma specimens, HPV 16 and HPV 52 were predominantly detected using the PCR method. Although some DNA samples extracted from the fluid-based specimens were degradaded, PCR and direct sequencing could be performed without difficulty even after 1 year of specimen storage. We conclude that fluid-based Papanicolaou specimens can be applied to investigate HPV infection.

Long-term follow-up of women with atypical squamous cells of undetermined significance (ASCUS)

ASCUS is the most common epithelial abnormality diagnosed in cytology laboratories in the US. Recently, the clinical importance of this diagnosis has been seriously questioned, with some investigators advocating elimination of this diagnostic category. This might be inappropriate if the ASCUS designation does define a population that is at significant risk for the development of dysplasia. Cytology and surgical pathology reports for all patients diagnosed as ASCUS in our laboratory during 1990 were reviewed. Patients with previous dysplasia or carcinoma were excluded from analysis. The pathology reports for the subsequent 9.1 yr were obtained and follow-up data collected. In 1990, 15,860 cervical cytology cases were examined in our laboratory. A diagnosis of ASCUS was made in 1,117 cases (7.0%). After excluding 345 patients with previous dysplasia or human papillomavirus-related diagnoses and 129 patients with no follow-up specimens, 643 study patients remained. Among these, the mean number of subsequent cervical smears was 4.3 (range, 1-18). Subsequent histologic material was available for 134 (20.8%) patients and the mean number of surgical specimens was 1.5 (range, 1-10). Squamous intraepithelial lesion (SIL) or dysplasia was subsequently diagnosed in 197 patients (30.6%). High-grade squamous intraepithelial lesion (HSIL) or at least moderate dysplasia was diagnosed in 64 patients (10.0%). In 21 cases (3.3%) the high-grade dysplasia developed more than 2 yr after the first ASCUS diagnosis. Follow-up disclosed no cases of invasive carcinoma. Among ASCUS patients followed for up to 9 yr, 20% develop only low-grade SIL or mild dysplasia and 10% develop HSIL or moderate or severe dysplasia. ASCUS should be retained as a diagnostic category since it identifies a significant percentage of patients who are at an increased risk for the development of cervical dysplasia.

Interobserver variability: comparison between liquid-based and conventional preparations in gynecologic cytology

BACKGROUND

Studies have shown that the ThinPrep Papanicolaou test (TP) increases the detection of epithelial cell abnormalities compared with the conventional preparation. Little is known about the interobserver variability of reporting gynecologic cytology results using the TP preparation and its comparison with results obtained using the conventional method.

METHODS

To compare the interobserver variability between the TP method and the conventional method for reporting the diagnoses of gynecologic cytology, 20 pairs of conventional and TP slides (total, 40 slides) that were prepared from split samples were evaluated blindly by 19 cytotechnologists from three different laboratories. Each reviewer was asked to categorize each slide into the following five categories: within normal limits, benign cellular changes, atypical squamous cells of undetermined significance, low-grade squamous intraepithelial lesion (LSIL), and high-grade squamous intraepithelial lesion (HSIL). For both conventional and TP preparations, interobserver variability was analyzed using Spearman rank correlation coefficients. The mean correlation coefficients (weak, 0.0-0.4; fair, 0.4-0.7; and strong, 0.7-1.0) between the TP method and the conventional method were then compared.

RESULTS

The overall interobserver agreement as well as interobserver agreement within each laboratory was good for both TP and conventional preparations. Based on the set of conventional cervical smears, only one slide that was diagnosed as HSIL had unanimous agreement; whereas, based on the set of TP slides, three slides, including two diagnosed as HSIL and one diagnosed as LSIL, had a unanimous diagnosis. The difference in the interobserver agreement between TP and conventional methods, based on comparing their mean +/- standard deviation correlation coefficients (TP method, 0.84 +/- 0.081; conventional method, 0.82 +/- 0.105; P < 0.001), was statistically significant.

CONCLUSIONS

Interobserver agreement in reporting gynecologic cytology using the TP method is good, particularly for squamous intraepithelial lesions, and appears to be superior to the conventional method.

Managing atypical squamous cells of undetermined significance (ASCUS): human papillomavirus testing, ASCUS subtyping,or follow-up cytology?

OBJECTIVE

This study related morphologic subtype, human papillomavirus status, and a second cytologic examination to the follow-up biopsy-proven high-grade squamous intraepithelial lesion (HSIL; grade II or III cervical intraepithelial neoplasia) after a cytologic diagnosis of atypical squamous cells of undetermined significance (ASCUS).

STUDY DESIGN

Seven hundred four liquid-based cervical cytology specimens were classified as normal, "ASCUS, favor reactive" (AFR), "ASCUS, not otherwise specified," "ASCUS, favor low-grade squamous intraepithelial lesion," "ASCUS, favor HSIL" (AFHS), low-grade squamous intraepithelial lesion, and HSIL. Human papillomavirus typing used polymerase chain reaction-restriction fragment length polymorphism analysis. A longitudinal review of the cytologic and histologic records of ASCUS cases with > or =1 follow-up test or biopsy ascertained the frequency of a follow-up diagnosis of biopsy-proven HSIL (grade II or III cervical intraepithelial neoplasia).

RESULTS

Three hundred eighty-six cases (208 ASCUS, 68 normal, 86 with low-grade squamous intraepithelial lesions, and 24 with HSIL) were evaluated. High-risk human papillomavirus (HRHPV positive) was lowest with normal cytology (13%), highest with HSIL (71%), and was present in 29.8% of ASCUS cases, ranging from 22.2% (AFR) to 75% (AFHS). Most ASCUS tests (64%) were followed by a negative cytologic or histologic examination. Overall, 3.8% and 11% of ASCUS and HRHPV-positive ASCUS had histologic outcomes of HSIL. AFHS had the highest (25%) and AFR had the lowest (1.1%) proportion of HSIL outcomes. Sensitivity, specificity, and positive predictive values of human papillomavirus testing for biopsy-proven HSIL were 87.5%, 72.5%, and 11.3%, respectively.

CONCLUSION

HSIL and AFHS are distinguished by the highest frequency of HRHPV types and higher rates of HSIL outcome. The remaining categories of ASCUS are heterogeneous with respect to human papillomavirus type and HSIL risk, and the value of subclassification of these entities is dependent on the practice. A human papillomavirus detection system based on polymerase chain reaction-restriction fragment length polymorphism identifies a smaller percentage of high-risk human papillomaviruses than mixed probe-based methods, probably because of the more precise exclusion of cross-reacting low-risk human papillomavirus. Negative HRHPV findings by either system show a markedly reduced risk of an HSIL outcome. However, the relative advantage of human papillomavirus testing over follow-up cytology will be influenced by the frequency of negative follow-up cytologic examination and sensitivity of liquid-based preparations in a given practice.

Significance of high-risk human papillomavirus detection by polymerase chain reaction in primary cervical cancer screening

The purposes of this study were to evaluate the incidence of high-risk human papillomavirus (HPV) infection by polymerase chain reaction (PCR) and to assess its diagnostic usefulness in primary cervical screening. PCR testing for HPV type 16, 18, 31 and 33 was performed on 1305 specimens obtained during routine cervical cancer screening. We analysed the concurrent cervical smears and biopsy, and correlated them with the HPV infection status. We also evaluated histologically-proven cases with ASCUS smears according to HPV infection. HPV DNA was identified in eight (0.7%) of 1144 cytologically normal patients; nine (10.5%) of 86 ASCUS; seven (25.0%) of 28 LSIL; 26 (78.8%) of 33 HSIL; and in all of three squamous cell carcinomas (SCC). HPV positivity was significantly associated with cytohistological diagnosis for HSIL of more. In addition, HPV-positive ASCUS cases were found to be associated with histological abnormality rather than HPV-negative. The results indicate that high-risk HPV testing by PCR could be a useful adjunct tool for Pap smear in primary cervical screening. The combination of Pap smear and high-risk HPV testing by PCR might reduce unnecessary colposcopy-guided biopsy of women with cytological diagnosis of ASCUS.

Diagnosing human papillomaviruses: recent advances

The biological importance of a group of human papillomaviruses, known as high-risk human papillomaviruses, as the key causal agent for almost all cervical cancer has now been established. Many aspects of the natural history of high-risk human papillomaviruses as sexually transmitted infections and as oncogenic agents have been researched. Although human papillomavirus diagnosis is largely confined to DNA detection techniques in cervical smears, there is accumulating evidence that the best polymerase chain reaction and hybrid capture techniques are more sensitive and probably of similar specificity compared with cervical cytology as a triage test for women with borderline smear abnormalities and for screening older women. This is strong presumptive evidence that high-risk human papillomavirus testing could be useful in cervical screening. Current research is aimed at establishing a place for high-risk human papillomavirus testing in routine screening practice. Randomised clinical trials, long-term natural history studies, mathematical modelling, and economic and psychosocial studies are being used to demonstrate whether this testing can improve both the effectiveness and efficiency of cervical screening in a range of situations.

Human papillomavirus typing in HIV-positive women

OBJECTIVE

Human papillomavirus (HPV) is the major cause of cervical carcinoma and cervical intraepithelial neoplasia worldwide. Certain HPV types have a strong association with and probably a causative role in the pathogenesis of premalignant cervical lesions. Epidemiologic studies in women infected by the human immunodeficiency virus (HIV) have shown an increased incidence of squamous intraepithelial lesions (SILs), which were predominantly high-grade. Six to 30 per cent of women diagnosed with atypical squamous cells of undetermined significance (ASCUS) on a Papanicolaou (Pap) smear harbor SIL in normal screening populations. This study was undertaken to determine the presence of low-and high-risk HPV types in women infected by HIV and to correlate the results to those of the Pap smear.

STUDY DESIGN

HPV DNA typing (low- and high-risk) by Digene (Digene Corporation, Gathesburg, MD) hybrid capture methodology was performed on cervical swabs from 209 HIV-positive women. The results of HPV typing were correlated with those of the Pap smear in a retrospective analysis.

RESULTS

One hundred and one women (48%) tested positive for HPV subtypes by DNA typing by the hybrid capture method. Of these, 64 patients (63%) had Pap smears which were read as being normal, having benign cellular changes, or having ASCUS (favor reactive process). Of these, 19 patients tested positive for both high-risk and low-risk subtypes, 32 patients tested positive only for high-risk subtypes, and 13 patients tested positive only for low-risk subtypes.

CONCLUSION

HPV subtyping identifies a significant group of HIV-positive women who are at risk for developing cervical intraepithelial neoplasia, although they may not show significant abnormalities on their Pap smears.

Prevalence of 'high risk' human papillomavirus in the lower genital tract of Brazilian gravidas

The presence of high-risk human Papillomavirus types 16, 18 and 33 was examined in 125 pregnant patients with abnormal Papanicolau smears. Specimens of cervicovaginal cells were analyzed by a simplified method of slot-blot hybridization. The overall prevalence of those viral sequences was 48%, being: 22.4% of HPV16, 17.6% of HPV18, 4.0% for double HPV16 and 18 infestation and 4.0% of HPV33. Their prevalence in HPV positive cervical sample was alone respectively 46.6%, 36.6%, 8.3% and 8.3%. Besides the high incidence of those carcinogenic types and intense viral proliferation, a rapid progression from CIN to carcinoma was clinically observed in four pregnant patients. Our data may reinforce the idea that progesterone has a positive role to the persistence and transformation of 'high risk' HPV, particularly of HPV16. The enhanced detection of potentially malignant types during pregnancy should warn on the importance of early diagnosis and treatment of papillomatosis.