Eliminating the diagnosis atypical squamous cells of undetermined significance: impact on the accuracy of the Papanicolaou test

OBJECTIVE: To assess eliminating the diagnosis "atypical squamous cells of undetermined significance" (ASCUS) from the Bethesda System for Reporting Cervical/Vaginal Cytological Diagnoses and analyze its impact on the sensitivity and positive predictive value of Pap smears. STUDY DESIGN: A total of 166 previously diagnosed ASCUS cases with follow-up biopsy results available were prospectively downgraded to within normal limits/benign cellular changes or upgraded to specific squamous intraepithelial lesions (SILs) or the malignant category. These review cytodiagnoses were compared with the histologic outcome. The impact on the sensitivity and positive predictive value of Pap smears was also assessed. RESULTS: Though there was a decrease in the sensitivity of the Pap smear from 100% to 76.3% for SIL overall and from 100% to 80% for high grade SIL (HSIL) alone, there was an improvement in the positive predictive value of diagnosing SIL from 46% to 85% and from 6% to 15% for HSIL alone. CONCLUSION: The ASCUS diagnosis can be minimized to a great extent, if not eliminated completely. The "ASCUS-favor reactive" group can be eliminated, while the diagnoses "ASCUS favor SIL" and "ASCUS-not otherwise specified" should be used sparingly.     

Clinical impact of atypical squamous cells of undetermined significance. A cytohistologic comparison

OBJECTIVE: To assess the percentage of squamous intraepithelial lesions (SILs) in the atypical squamous cells of undetermined significance (ASCUS) cytologic diagnosis. STUDY DESIGN: From January 1994 to December 1995, 421 cervical Pap smears with a diagnosis of ASCUS were followed with cervical biopsies within three months. The ASCUS cytologic diagnosis was correlated with the histologic findings and stratified according to age group, previous abnormal history and cell type of ASCUS (squamoid vs. metaplastic). RESULTS: Histologic diagnosis showed that of ASCUS diagnoses, 13% were normal, 34% were reactive, 4.8% were atypical, 43% were low grade SIL, 4% were high grade SIL, 1% were carcinoma in situ, and none were invasive lesions. The patients in the youngest group, up to 25 years, demonstrated the highest percentage of SIL. Patients with a previous abnormal gynecologic history showed a higher percentage of SIL than those without an abnormal history. SILs were observed in 51.5% of squamoid ASCUS and 36.5% of metaplastic ASCUS. CONCLUSION: Forty-eight percent of females having an ASCUS diagnosis on Pap smears had SIL and thus a preneoplastic lesion. The highest percentage of SIL was found in females 25 years and younger. Our findings suggest that an ASCUS diagnosis warrants ongoing follow-up.     

Outcomes of women with atypical squamous cells of undetermined significance and high-risk human papillomavirus DNA

OBJECTIVE: To study the risk of high-grade squamous intraepithelial lesion (HSIL) and cervical intraepithelial neoplasia (CIN) 2 or 3 in women with human papillomavirus (HPV)-positive atypical squamous cells of undetermined significance (ASCUS) cytology over a 2-year period using the 2001 Bethesda System and ThinPrep Paps. STUDY DESIGN: In 2002, 846 patients with ThinPrep cervical cytology having an ASCUS interpretation and positive for high-risk HPV DNA were identified. A cohort of 514 (60.8%) patients with follow-up by repeat cytology, cervical biopsy or both was included in the study. Patient age was 12-81 years, with a median of 25 years. RESULTS: There were 291 women (56.6%) with negative status by cytology, HPV testing or biopsy with a median interval of 8.5 months, and an additional 174 patients (33.9%) had persistent ASCUS, positive HPV DNA or low-grade SIL/CIN 1. Finally, 49 patients (9.5%) had CIN 2 or 3, with a median interval of 8.5 months. CONCLUSION: Our study suggests that HSIL or CIN 2 or 3 will be detected in 1 in 10 women with HPV-positive index ASCUS cervical cytology at initial colposcopy or within a 2-year follow-up period.     

Interlaboratory reproducibility of atypical squamous cells of undetermined significance report: a national survey

The study was aimed at assessing interlaboratory reproducibility in the reporting of cervical smears in the atypical squamous cells of undetermined significance (ASCUS) category. A set of 50 selected slides circulated among 89 laboratories, currently involved in population-based screening programmes for cervical cancer, which provided a diagnostic report according to four main reporting categories based on the 1991 Bethesda system. Interlaboratory agreement was determined according to kappa (K) statistics: overall and weighted K values were determined for each laboratory and for single reporting categories. The results showed a very low reproducibility for the ASCUS category. This finding supports the Bethesda system 1991 recommendation to limit the use of this reporting category and suggests that the clinical response to ASCUS reports should be decided locally, based on the observed positive predictive value for cervical intraepithelial neoplasia 2 or more severe lesions.     

Variables associated with squamous intraepithelial lesions among women with a cytologic diagnosis of atypical squamous cells of undetermined significance.

OBJECTIVE: To identify factors among women with atypical squamous cells of undetermined significance (ASCUS) cytologic diagnosis that are associated with either low grade squamous intraepithelial lesions (LSILs) or high grade squamous intraepithelial lesions (HSILs). STUDY DESIGN: From January 1992 to June 1995, 1,660 women with a diagnosis of ASCUS were followed until the next follow-up appointment after the ASCUS diagnosis. Logistic regression analysis with either LSIL or HSIL at follow-up examination as a dependent variable was done with the following independent variables: patient age, method of follow-up, follow-up time, type of health care coverage and household income. RESULTS: In multivariate analyses, there was a 2.7-fold increase in the odds of LSIL (OR = 2.7, 95% CI = 1.3-5.8) for young women (< or = 25 years), a 2-fold decrease in the odds of LSIL (OR = .5, 95% CI .3-.9) for long time to follow-up (> 18 weeks after ASCUS diagnosis) and an 7.8-fold increase in the odds of LSIL (OR = 7.8, 95% CI = 5.1-11.9) for follow-up by colposcopic biopsy. For the odds of HSIL, there was a 6.8-fold increase (95% CI = 3.2-14.5) for follow-up by colposcopic biopsy as compared to Pap smears and a 3-fold decrease in the odds of HSIL (OR = 3, 95% CI = .1-.7) for high-income women (> $34,857). CONCLUSION: Our findings suggest that among ASCUS patients, younger women and those with shorter follow-up time are more likely to be diagnosed with LSIL. Women with a high income showed a protective association for HSIL. Colposcopic biopsy identified more LSIL and HSIL as compared to repeat Pap smear.     

Clinical significance of atypical glandular cells of undetermined significance. A follow-up study from an academic medical center

OBJECTIVE: To determine the rate of atypical glandular cells of undetermined significance (AGUS) and the incidence of subsequent clinically significant lesions. STUDY DESIGN: A computer-based search of our cytology laboratory files was performed for cervicovaginal smears diagnosed as AGUS from January 1996 to December 1996. RESULTS: In 43,456 cervicovaginal smears examined during the 12-month period, AGUS was reported in 222 (0.5%) cases, with follow-up in 191 (86.0%) (133 [59.9%] biopsies and 58 [26.1%] repeat cervicovaginal smears). Among the patients with repeat cervicovaginal smears, 1 (1.7%) had a high grade squamous intraepithelial lesion, and 10 (17.2%) had persistent AGUS/atypical squamous cells of undetermined significance; the remainder were within normal limits. Thirty-three (24.8%) patients had preneoplastic or neoplastic, squamous or glandular lesions on biopsy (8 [6.0%] cervical intraepithelial neoplasia [CIN] 1, 18 [13.5%] CIN 2/3 and 7 [5.3%] endometrial adenocarcinomas). Half the patients with CIN 2/3 also had evidence of endocervical gland involvement. Squamous lesions were seen more commonly in premenopausal women, while glandular lesions were noted predominantly in postmenopausal women. Patients with a prior abnormal gynecologic history or a concomitant diagnosis of squamous intraepithelial lesion (SIL) had a higher incidence of significant lesions on subsequent biopsy. CONCLUSION: Our incidence of AGUS was 0.5%, similar to that in other published reports. AGUS is associated with a significant number of squamous or glandular, premalignant or malignant lesions. A majority of these lesions are high grade SIL, often with endocervical gland involvement. A small but significant number of patients had a glandular malignancy. Our results justify close and persistent follow-up for patients with a diagnosis of AGUS on cervicovaginal smears.     

HPV triage of women with atypical squamous cells of undetermined significance: a 3-year experience in an Italian organized programme

OBJECTIVE: The purpose of our study was to determine if Hybrid Capture II assay (HCII) on Liquid Based Cytology (LCB) improves the accuracy (higher sensitivity, similar specificity) than the repeat conventional Pap smear in smears with Atypical Squamous Cell (ASC) of Undetermined Significance diagnosis. METHODS: HPV testing was used to manage women, especially the older ones, with cervical abnormalities detected through our triennial organized screening in order to avoid unnecessary colposcopy and excessive follow-up if the woman is HPV negative. The HPV DNA Triage was offered without any charge to 909 women with ASC. The Bethesda System was used for the classification of these equivocal cytological findings and more precisely the 1991 version (ASCUS) until the summer 2001 (315 cases) and the new one 2001 classification (ASC-US and ASC-H) after this date (594 cases). The presence or absence of a cervical intraepithelial neoplasia of grade I or worse [CIN1+], and of grade II or worse [CIN2+], was confirmed by biopsy. RESULTS: The HPV DNA Triage showed a good accuracy (specificity over 94%, sensitivity of 37% and PPV for CIN2+ lesions around 30%). The higher values of ASC-H lesions (.462) for the sensitivity for CIN 2+ probably signify that this lesion is already a SIL. CONCLUSIONS: Our data were comparable with those recently published on the meta-analysis by Arbyn et al., confirming the promising approach of our guidelines for the treatment of these patients even in terms of Health Technology Assessment (HTA).     

Significance of high-risk human papillomavirus DNA-positive atypical squamous cells of undetermined significance pap smears in perimenopausal and postmenopausal women

OBJECTIVE: To determine the risk of high-grade squamous intraepithelial lesion (HSIL)/cervical intraepithelial neoplasia (CIN) 2 or 3 in perimenopausal and postmenopausal women with high-risk human papillomavirus (HPV) DNA-positive atypical squamous cells of undetermined significance (ASCUS) on Pap tests. STUDY DESIGN: A total of 752 perimenopausal and postmenopausal women (patients 45 years) with an ASCUS interpretation on ThinPrep Pap tests were identified in 2002 and 2003. High risk HPVDNA was detected in 191 (25.4%) women. The follow-up results in these 136 women were compared with those of women <45 years. RESULTS: Of the 136 perimenopausal and postmenopausal women, 64.7% became negative on cytology or biopsy and 30.9% revealed persistent low-grade SIL (LSIL)/CIN 1. Furthermore, 5 women (3.68%) were diagnosed with HSIL/CIN 2 or 3, and 1 patient had squamous cell carcinoma (0.74%). The rate of HSIL/CIN 2 or 3 or worse detected in perimenopausal and postmenopausal women was significant lower than 10.6% in women <45 years (p = 0.028). CONCLUSION: Our study showed that perimenopausal and postmenopausal women with high-risk HPV positivity and an ASCUS interpretation have a significantly lower risk of HSIL/CIN 2 or 3 detected. Nonetheless, the risk of a significant finding on workup, including invasive carcinoma, indicates the need for colposcopic evaluation of these women.     

Interlaboratory reproducibility of atypical glandular cells of undetermined significance: a national survey

OBJECTIVE: The aim of this study was to evaluate the inter-laboratory reproducibility for atypical glandular cells (AGC) (The Bethesda System (TBS) 2001) of the laboratories involved in the screening programmes in Italy. METHODS: A set of 35 selected slides were circulated among 167 laboratories involved in local population-based cervical screening programmes. Each laboratory provided one single diagnosis per smear. The smears were read blind to the original diagnosis and to the diagnoses provided by other laboratories. A 'majority' diagnosis was defined for each case and assumed as the reference standard. The diagnosis provided from each laboratory was compared with the majority diagnosis. RESULTS: According to the majority report the 35 slides in the set were classified as negative in nine cases, AGC in eight, adenocarcinoma in eight, and squamous lesion or squamous + glandular lesion in 10. The crude agreement between all pairs of laboratories was 49.43%. K-values were 0.46, 0.21, 0.34, 0.36 and 0.32 for negative, AGC/AIS (adenocarcinoma in situ of endocervix), AdenoCa, Sq/Sq + Gl and all reporting categories respectively. Concordance according to overall K was moderate to substantial in 77% of the participating laboratories. CONCLUSIONS: The present study shows that the AGC category is not easily reproducible. The data confirmed the importance, in a screening scenario, of AGC/AIS diagnoses, but also presented difficulties in differentiating between the two diagnoses. In addition to the results obtained from the circulation of the slides, laboratories which had annually a low number of cervical smears were able to gain experience focused on particular morphological pictures.     

Morphologic, patient and interpreter profiles of high-risk human papillomavirus-positive vs.-negative cases of atypical squamous cells of undetermined significance

OBJECTIVE: To define the morphologic and patient profiles, if any, that distinguish high-risk human papillomavirus (HR-HPV)-positive atypical squamous cells of undetermined significance (ASCUS) from HR-HPV-negative ASCUS and to compare individual and laboratory reporting rates with the national averages. STUDY DESIGN: One hundred fifty liquid-based cervicovaginal preparations (ThinPrep, Cytyc Corporation, Boxborough, Massachusetts, U.S.A.) with a diagnosis of ASCUS and a reflex HR-HPV test were assessed for the following features: background patient information, cell morphology, cell patterns and interpreter profiles. Fisher's Exact test (2-tailed) was used to calculate the exact probability of obtaining results by chance. RESULTS: The median age of the HR-HPV-positive patients was approximately 11 years younger than the HPV-negative group, and pregnant patients were also more apt to be HPV positive. Atypical cells in greater numbers and in groups as opposed to single cells correlated more often with HR-HPV-positive individuals. Koilocytelike changes and parakeratosis were more frequently associated with HR-HPV, but the presence of Trichomonas was usually a negative predictor. CONCLUSION: In cases diagnosed as ASCUS, there are certain cytologic features and patient types that are more likely to be associated with HR-HPV positivity. This could be used in everyday practice to further fine tune the diagnosis of ASCUS. Monitoring individual and laboratory ASCUS rates with HR-HPV positivity can be an important quality improvement indicator.     

High-risk HPV DNA detection rate in patients with atypical squamous cells and its relationship to the atypical squamous cell: squamous intraepithelial lesion ratio

OBJECTIVE: To determine if there is any relationship between the atypical squamous cell (ASC):squamous intraepithelial lesion (SIL) ratio and high-risk HPV DNA detection rate. STUDY DESIGN: Data on the frequency of various cytologic diagnoses for each pathologist were retrieved from 2002 to 2003. ASC:SIL ratio for each pathologist was calculated. In addition, data related to high-risk HPV detection rate was obtained during the study period. HPV DNA testing was performed using HC II (Digene, Gaithersburg, Maryland U.S.A). Cases with insufficient quantity were excluded. RESULTS: Five pathologists, with experience ranging from 2 to 15 years, reviewed Pap tests during the study period. For the entire laboratory, the ASC:SIL ratio was 2.0, and the high-risk HPV DNA detection rate in ASC specimens was 31%. For individual pathologists, ASC:SIL ratio ranged from 1.2 to 4.0 and high-risk HPV DNA detection rate from 31% to 38%. No significant correlation was noted between the ASC:SIL ratio and high-risk HP DNA detection rate. CONCLUSION: Our ASC:SIL ratios (except for 1 pathologist) and high-risk HPV DNA detection rates were within an acceptable range. We did not observe any association between ASC:SIL ratio and high-risk HPV detection rate.     

Histologic follow-up of atypical endocervical cells. Liquid-based,thin-layer preparation vs. conventional Pap smear

OBJECTIVE: To review the histologic findings in patients diagnosed with "atypical glandular cells of uncertain significance, endocervical cell type" (AGUS-EC) by ThinPrep Pap Test (TPPT) or conventional Pap smear (CPS) and to evaluate the clinical value of subclassifying AGUS-EC as "favor reactive" or "favor neoplastic." STUDY DESIGN: All TPPT and CPS diagnosed as AGUS-EC (favor reactive, unspecified and favor neoplastic) from January 1998 through December 1999 and all available histologic follow-up (defined as endocervical curettage, cervical biopsy, cervical conization or hysterectomy obtained within six months of the time of an AGUS-EC diagnosis) were obtained from a computerized database. RESULTS: AGUS-EC was diagnosed in 0.77% of CPS (683 of 88,825) and 0.59% of TPPT (183 of 30,968) (P = NS). There was no statistically significant difference in any of the follow-up histologic diagnoses between the CPS and TPPT groups. The majority of the follow-up biopsies demonstrated benign processes in both groups. Patients with a diagnosis of AGUS-EC "favor neoplastic" had a greater proportion of true glandular pathology as compared with AGUS-EC "unspecified" or "favor reactive" (P < .001). None of the patients with a diagnosis of AGUS-EC "favor reactive" were found to have true glandular pathology; however, a minority of them proved to have squamous pathology. CONCLUSION: In this study there was no difference in CPS and TPPT in regard to the specificity of a diagnosis of AGUS-EC for true glandular pathology. Subclassifying AGUS-EC as "favor reactive" or "favor neoplastic" may provide valuable information for directing patient follow-up.     

Atypical squamous cells of undetermined significance in women over 55. Comparison with the general population and implications for management.

OBJECTIVE: To determine the significance of atypical squamous cells of undetermined significance (ASCUS) in patients 55 years or older. STUDY DESIGN: From January 1994, to January 1997, 8,175 cervicovaginal smears were obtained from patients 55 years or older (mean age, 64.8; range, 56-84) at University Hospitals of Cleveland. Ninety-six of these patients were diagnosed with ASCUS only or ASCUS with a qualifying statement on the smear. Patient records, follow-up cervicovaginal smears and biopsies were reviewed for a period of one to four years following the diagnosis of ASCUS. RESULTS: The incidence of ASCUS only or ASCUS with a qualifying statement for patients 55 years or older was 1.8%. The ASCUS:SIL ratio was 2.6:1. An estrogen stimulation test was recommended in two cases. Women older than 55 with ASCUS were three times more likely to be receiving hormonal replacement therapy than similar-aged women with normal cervicovaginal smears. Follow-up cervicovaginal smears or biopsies were obtained on 93 (80 cervicovaginal smears, 13 biopsies). The results were the following: LSIL (13), squamous carcinoma in situ (1) and ASCUS (53); the remainder of the cases were normal. In the patients who received a second diagnosis of ASCUS, follow-up cervi covaginal smears or biopsies revealed low grade dysplasia in six. CONCLUSION: Although the incidence of ASCUS and the frequency of underlying dysplasia is lower in postmenopausal women than the general population, there is still a real risk that a postmenopausal woman with ASCUS has underlying intraepithelial neoplasia. Therefore, these patients should be managed as is the general population.     

Atypical glandular cells of undetermined significance. Cytologic predictive value for glandular involvement in high grade squamous intraepithelial lesions

OBJECTIVE: To verify the cytologic predictive value of a diagnosis of atypical glandular cells of undetermined significance (AGUS) in high grade squamous intraepithelial lesions (HSIL) cases. STUDY DESIGN: In a retrospective study, 98 cases of HSIL were reviewed. All patients were referred for colposcopy and directed biopsy to confirm the cytologic diagnoses. Loop excision of the transformation zone was performed to treat clinical lesions. Sensitivity, specificity, positive and negative predictive value were evaluated. Kappa statistics and logistic regression analysis were used to evaluate the findings statistically. RESULTS: By logistic regression analysis, we found that the chance of finding squamous intraepithelial lesions involving glands in AGUS smears was 5.32 times higher than in those with no AGUS. It was 5.74 times higher in cervical intraepithelial neoplasia (CIN) 3 lesions than in CIN 2. CONCLUSION: The cytologic predictive value for HSIL involving glands is statistically significant when specific and objective criteria are used for the AGUS diagnosis.     

Comparison of the clinical performance of an HPV mRNA test and an HPV DNA test in triage of atypical squamous cells of undetermined significance (ASC‐US)

M. Waldstrom and D. Ornskov
Comparison of the clinical performance of an HPV mRNA test and an HPV DNA test in triage of atypical squamous cells of undetermined significance (ASC‐US) Objective: The effect of triaging women with atypical squamous cells of undetermined significance (ASC‐US) with human papillomavirus (HPV) DNA testing has been well documented. New tests detecting HPV E6/E7 mRNA are emerging, claiming to be more specific for detecting high‐grade disease. We evaluated the clinical performance of two HPV tests: the Linear Array HPV genotyping test (LA) detecting HPV DNA from 37 oncogenic and non‐oncogenic HPV types and the Aptima HPV assay detecting E6/E7 mRNA from 14 oncogenic HPV types. Methods: We identified 369 consecutive PreservCyt samples diagnosed with ASC‐US tested for HPV DNA using the LA test. The Aptima HPV test was performed on residual material in the same vial. Follow‐up of 325 women was available. The gold standard used was histologically confirmed cervical intraepithelial neoplasia (CIN) grade 2+ or 3+. Results: LA and Aptima HPV assays were positive in 44.3% and 31.7% of the cases, respectively. The concordance was 81.2%. The two tests had identical sensitivity for detecting CIN3+ [92.6% (95% CI, 75.7–99.1)] but the Aptima HPV assay showed a significantly better specificity of 73.8% (95% CI, 68.5–78.7) versus 60.1% (95% CI, 54.3–65.7) for LA for detecting CIN3+. When using CIN2+ as the gold standard the sensitivity for LA was higher than for the Aptima HPV assay [93.8% (95% CI, 82.8–98.7) versus 87.5% (95% CI, 74.8–95.3)], but the specificity was higher for the Aptima HPV assay: 78.0% (95% CI, 72.6–82.7) versus 64.3% (95% CI, 58.3–69.9). Conclusions: Both tests showed good and equal clinical sensitivities for detecting CIN3+, but the Aptima HPV assay had significantly higher specificity for detecting CIN2+ and CIN3+ in women aged 30 years or older with ASC‐US.     

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'.