Significance of atypia in conventional Papanicolaou smears and liquid-based cytology: a follow-up study

The diagnosis of atypical squamous epithelial cells, borderline nuclear changes, is associated with some controversy, as it encompasses benign, reactive, as well as possible neoplastic conditions. The aim of this study was to evaluate the follow-up diagnoses of cytological atypia in conventional Papanicolaou smears (CP) and liquid-based samples by the ThinPrep Pap Test (TP). A total of 1607 CP smears from 1 January 2000 to 31 December 2000 and 798 TP samples from 1 January 2002 to 31 December 2002 diagnosed as atypia were included. The results show that the detection rate of atypia in cervical cytological samples was reduced by 41.3% (P < 0.001) in TP compared with CP. Cytological and histological follow-up data showed the presence of neoplastic lesions in 34.7% of patients screened by TP versus 22.3% of patients screened by CP, corresponding to a 55.6% increase in TP (P < 0.001). Follow-up diagnosis of mild dysplasia was seen more than twice as often in TP than in CP (12.8% versus 5.0%, P < 0.001). The prevalence of moderate and severe dysplasia was significantly increased with 26.7% in TP compared with CP (21.9% versus 17.2%, P < 0.01). In conclusion, the ThinPrep Pap Test yielded a significant decrease in atypia rates compared with the conventional Papanicolaou test. In subsequent follow-up the percentage of neoplastic lesions was significantly increased in the ThinPrep Pap Test samples.     

HPV-DNA 亚型检测联合液基细胞学对宫颈癌 筛查的临床价值

目的:探讨HPV-DNA亚型检测联合液基细胞学对宫颈癌筛查的临床价值.方法:对自愿接受宫颈癌筛查的女性1462例作为研究对象,分别对其进行HPV-DNA亚型检测以及液基细胞学的检查,对于出现阳性的患者进行病理组织学检查.结果:HPV+TCT对宫颈癌早期病变以及癌变的检出率为69.67％明显高于HPV检查的56.28％以及TCT检查的63.89％(P＜0.05);HPV+TCT对GIN Ⅰ、CIN Ⅱ、CINⅢ、癌的检出率分别为91.67％,92.86％、91.67％以及100％.结论:采用HPV-DNA亚型检测联合液基细胞学对宫颈癌筛查,可明显提高其对癌前病变的检出率,是一种高效、简单的检测方法.     

Endoscopic ultrasound‐guided fine needle aspiration of the pancreas: cytomorphological evaluation with emphasis on adequacy assessment,diagnostic criteria and contamination from the gastrointestinal tract1

Objective: Endoscopic ultrasound (EUS)‐guided fine needle aspiration (FNA) has been proved to be safe, efficient and reliable in the diagnosis of pancreatic lesions. This study evaluated specimen adequacy, diagnostic criteria of various pancreatic neoplasms and contamination from the gastrointestinal (GI) tract. Methods: EUS‐guided FNA of the pancreas and subsequent surgical resections performed at the University of California Irvine Medical Center during February 1996–October 2000 were retrospectively selected. Modified Papanicolaou staining method was used for immediate evaluation and cell block prepared. Results: A total of 267 cases were available for review, including 147 (55.1%) positive/suspicious, 10 (3.7%) atypical, 96 (36.0%) negative and 14 (5.2%) unsatisfactory cases. Eighty‐six (58.5%) positive/suspicious cases had histological confirmation and 12 (8.3%) had lymph node or distant metastases by cytology. Three atypical, two negative, and two unsatisfactory cases proved to have adenocarcinoma. Contamination from duodenum, stomach or pancreas was found in 77 positive/suspicious, three atypical and 90 negative cases. The sensitivity, specificity, diagnostic accuracy, positive and negative predictive values were 94.6%, 100%, 95.6%, 100%, 82% respectively. Conclusions: EUS FNA is efficient and accurate in the diagnosis of pancreatic neoplasms in adequate samples. Contamination from the GI tract should be well recognized to avoid misinterpretation.     

Endometrial carcinoma detected with SurePath liquid-based cervical cytology: comparison with conventional cytology

Introduction: Conventional Pap smears (CPS) have little impact on the detection of endometrial carcinoma. Although liquid‐based cytology (LBC) is replacing CPS in the UK, experience with identification of endometrial cancers with this technique is limited. Aim: To compare the accuracy of the SurePath LBC with that of CPS for detection of endometrial cancers. Methods: Our study group comprised SurePath LBC samples reported as atypical endometrial cells and endometrial adenocarcinoma (classified respectively as borderline, code 8 and ?glandular neoplasia, code 6 for the NHS Cervical Screening Programme statistics) in 2004–2005. CPS reported as atypical endometrial cells or adenocarcinoma in 1993–1998 comprised the control group. Histological follow‐up was obtained. Results: Endometrial abnormalities were reported in 95 (0.073%) of 130 352 LBC samples, comprising 75 (0.058%) atypical endometrial cells and 20 (0.015%) endometrial adenocarcinoma reports. Of 409 495 CPS, 117 (0.029%) were diagnosed as endometrial abnormalities, comprising 59 (0.014%) atypical endometrial cells and 58 (0.014%) endometrial adenocarcinoma reports. Thus, the endometrial adenocarcinoma reporting rate was similar in both groups, but that for atypical endometrial cells was higher with LBC (P < 0.001). The positive predictive value for endometrial cancer of endometrial adenocarcinoma and atypical endometrial cell reports in the LBC group was 73.3 and 18.8%, respectively, compared with 42.3 and 6.7% in the CPS group. The endometrial adenocarcinoma patients in CPS group were older (mean age 62.5 years versus 56.5 years) and most (22/25) were symptomatic, whereas most (13/17) patients in the LBC group were asymptomatic at the time of sampling (P < 0.001). Conclusion: SurePath LBC is at least as accurate a method for detecting endometrial cancer as CPS. SurePath LBC demonstrates enhanced identification of endometrial pathology in asymptomatic women in the cervical screening programme.     

Transformation zone sampling rate is a useful performance indicator for practitioners collecting cervical samples using SurePathTM liquid-based cytology system

An analysis of the reports of 53 982 liquid-based cytology (LBC) samples processed at the Royal Victoria Infirmary, Newcastle, reveals a significant relationship between the transformation zone (TZ) sampling rate observed in specimens submitted from different practices and their overall detection rate for dyskaryosis. The observed correlation (R = 0.184; P = 0.033, CI = 0.017 to 0.397) is very similar to that described previously using conventional cervical smears and confirms the potential relevance of TZ sampling rates as an indicator of consistently effective specimen collection. The correlation between unsatisfactory sample rates and detection rates for high-grade dyskaryosis (R = -0.188, P = 0.030, CI = -0.865 to -0.045) also shows a significant relationship for LBC samples which was not previously seen in conventional smears. The essential role of smear taker feedback, the use of transformation zone sampling and unsatisfactory smear rates as key indicators and the practical issues relating to routine reporting of transformation zone components are discussed.     

Primary screening with liquid-based cytology in an unscreened population in rural China,with an emphasis on reprocessing unsatisfactory samples

OBJECTIVE: To determine the sensitivity and specificity of liquid-based cytology in a high-risk, unscreened population. STUDY DESIGN: A cross-sectional comparative trial of multiple screening techniques. This report focuses on the performance of liquid-based cytology using biopsy as the standard. RESULTS: In total, 1,997 women were screened. All subjects had a minimum of five cervical biopsies. Of the subjects, 4.3% had CIN 2 on biopsy. The ThinPrep Pap with ASCUS as positive had a sensitivity for CIN 2 of 94% and specificity of 78%; the sensitivity for CIN 3 was 98% and for cancer, 100%. The unsatisfactory rate due to bloody specimens was 7.9% (158/1,997). After reprocessing, the unsatisfactory rate was 0.15% (3/1,997). CONCLUSION: Reprocessing effectively recovers ThinPrep samples otherwise unsatisfactory due to blood and mucus. The ThinPrep Pap test is a highly sensitive screening test when used in a high-risk, unscreened population.     

Cell block as an adjunct to conventional Papanicolaou smear for diagnosis of cervical cancer in resource-limited settings

OBJECTIVE: To assess the utility of indigenously prepared cell blocks (CBs) as an adjunct to a conventional smear test in providing a reliable diagnosis of clinically suspicious cervical cancer in resource-limited settings. METHODS: Eighty-six clinically suspicious cervical cancer cases underwent a conventional smear test, CB preparation from residual cellular samples and biopsies at the same sitting. Correlations were performed between these modalities in order to derive the sensitivity and specificity of the CB technique to diagnose cervical cancer. OBSERVATION & RESULTS: Out of 86 clinically suspicious cervical cancers, 72 (83.7%), 70 (81.4%) and 67 (77.9%) cases were diagnosed as malignant on tissue biopsies, CBs and smears respectively. CB-biopsy agreement in the diagnosis of malignancy was feasible in 87.5% of the cases while CB-Pap smear agreement was feasible in 92.5% of the cases. Sensitivity and specificity of CB preparation to diagnose malignancy was 92.5% and 100%, respectively, when the smear was taken as the reference test (excluding the unsatisfactory smears). When biopsy was taken as the gold standard, the sensitivity and specificity of CBs were 87.5% and 100% respectively (excluding the unsatisfactory biopsies). In 8/19 cases where the smear diagnoses were either unsatisfactory or atypical squamous cells/atypical glandular cells, CBs picked up malignant lesions. CONCLUSION: CBs prepared from the residual cellular sample of conventional cervical scrapes augment the sensitivity of the smear test. When used as an adjunct to the smear, CBs aid in providing a reliable diagnosis of cervical cancer in the majority of the clinically suspected cases and thus the biopsy load can be reduced significantly in resource-poor settings.     

Implementation of liquid-based cytology in the screening programme against cervical cancer in the County of Funen, Denmark, and status for the first year

As one of the first laboratories in Denmark (and Scandinavia), we have gradually implemented liquid-based cytology into the screening programme against cervical cancer in the County of Funen since 1 June 2001. This paper describes the course of the implementation period in the different steps in the screening programme, and the preliminary results obtained after the first year. We conclude that the new technique has improved the specimen and diagnostic quality. As a result of the reduction of the screening time, the workload in the laboratory is in balance although we have introduced a rapid review as a quality control. Besides, the reduction in the number of repeated cytological tests and follow-up visits at the gynaecologist means a saving for the screening programme as a whole. From our point of view the implementation of ThinPrep method is economically neutral.     

Chlamydia trachomatis detection in cervical PreservCyt specimens from an Irish urban female population

Objective:  The aim of this study was to determine the prevalence of cervical Chlamydia trachomatis infection by polymerase chain reaction (PCR) in urban women undergoing routine cervical cytological screening and to investigate the relationship with age, cytology, smoking status and concurrent human papillomavirus (HPV) infection.
Methods:  A total of 996 women (age range 16–69 years) attending general practitioners for routine liquid-based cervical smear screening in the Dublin area were recruited in the study of prevalence of C. trachomatis . Informed consent was obtained and liquid-based cytology (LBC) specimens were sent for cytological screening. DNA was extracted from residual LBC and tested for C. trachomatis by PCR using the highly sensitive C. trachomatis plasmid (CTP) primers and for HPV infection using the MY09/11 primers directed to the HPV L1 gene in a multiplex format.
Results:  The overall prevalence of C. trachomatis was 5.4%. Prevalence was highest in the <25 years age group (10%). Coinfection with HPV and C. trachomatis occurred in 1% of the screening population. A higher rate of smoking was observed in women positive for C. trachomatis , HPV infections or those with abnormal cervical cytology. Chlamydia trachomatis infection was not associated with abnormal cytology.
Conclusions:  Women (5.4%) presenting for routine cervical screening are infected with C. trachomatis . Opportunistic screening for C. trachomatis from PreservCyt sample taken at the time of cervical cytological screening may be a possible strategy to screen for C. trachomatis in the Irish female population.     

薄层液基细胞学检查在宫颈普查中应用的临床分析

目的:评价薄层液基细胞学检查在宫颈普查中应用的临床价值。方法:选择经薄层液基细胞学门诊普查妇女520例,其中经TCT检查结果提示ASCUS以上的妇女76例,均进一步采取阴道镜下宫颈活检病理检查,将TCT检查结果与阴道镜下宫颈活检病理检查结果对比分析。结果:TCT检查结果具有较高的检出率及符合率,HSIL组、SCC组与LSIL组符合率比较,差异具有统计学意义(P<0.05)。结论:TCT检查作为妇科宫颈普查的方法,具有检出率及符合率高的优点;检查结果为HSIL或SCC时,应引起临床极高度重视。     

Assessing the wellbeing of cytoscreeners: experience in two NHS cytology laboratories

OBJECTIVE: Cervical screening programmes in England are in transition as the liquid-based cytology (LBC) method replaces conventional Papanicolaou screening and staff in NHS laboratories are trained to analyse LBC smears. Cytoscreeners and biomedical scientists undertake routine microscopy of slides, but the scientists usually have a wider professional role. Attitudinal surveys were carried out in laboratories where LBC was partially introduced. METHODS: Staff in two cytology laboratories in Greater Manchester were surveyed twice over 6 months. The questionnaire assessed work pressures using scales from the Measures of Work Characteristics instrument, work-related stress using the General Survey version of the Maslach Burnout Inventory, job intentions and job satisfaction. RESULTS: Cytoscreeners, many aged over 50 years, formed over 60% of respondents in both surveys (27/42 in the first survey), and biomedical scientists and doctors, 30%. Both groups were under moderate pressure from work demands in each survey, but cytoscreeners had significantly less autonomy over their working methods (P < 0.001). Although both groups experienced similar levels of exhaustion, cytoscreeners were much more cynical or indifferent towards work in the second survey (P = 0.008) and had lower expectations of being effective (P < 0.001). For the cytoscreeners, there were strong negative correlations in both surveys between cynicism and the work characteristics of influencing decisions and autonomy/control. CONCLUSIONS: The strength of the relationship between work performance and wellbeing serves to emphasize the importance of the new LBC technology in ameliorating low morale where it exists. Further attitudinal research involving larger samples of laboratories is warranted to assess the full impact of this innovation.     

Determination of liquid-based cervical cytology specimen adequacy using cellular light scatter and flow cytometry.

BACKGROUND: The majority of cervical cytology specimens are being collected in liquid-based preservatives (LBP). However, the assessment of specimen adequacy, as mandated by The Bethesda System (TBS), is still being performed at the time of slide review. We present a rapid, flow cytometric method for assessing specimen adequacy. METHODS: Three LBPs were compared for cell-surface antigen preservation. A three-color antibody panel was used to confirm the light scatter profile of specific cells in a liquid-based cervical cytology specimen. Using forward and orthogonal light scatter alone, we were able to assess the adequacy of liquid-based cytology specimens in all LBPs tested. RESULTS: The number of polymorphonuclear neutrophils (PMNs), endocervical (columnar) cells, ectocervical (squamous) cells, and debris in 120 liquid-based cervical cytology samples was quantified in less than 10 min. Using cutoffs of > 20% PMNs, < 1.0% endocervical cells, < 1.0% ectocervical cells, and < 500 total cells per milliliter, light scatter correlated with microscopic determination of adequacy with a correlation coefficient of 0.99. CONCLUSIONS: This rapid method allows the quantitative determination of cervical cytology adequacy in liquid-based cytology preparations prior to the preparation of slides for morphologic assessment.     

Applicability of liquid-based cytology to the assessment of DNA content in cervical lesions using static cytometry

OBJECTIVE: To evaluate the nuclear DNA content of cervical lesions in liquid-based cytologic specimens prepared for static cytometry. STUDY DESIGN: The DNA content of cervical lesions was evaluated in cervical samples prepared with the Autocyte PREP liquid-based cytology system (TriPath Imaging Inc., Burlington, North Carolina, U.S.A.). A series of 47 samples stained with the Papanicolaou method (chronic cervicitis, n = 15; cervical intraepithelial neoplasia [CIN] 1, n = 25; CIN 2, n = 5; CIN 3, n = 2) were collected from consecutive women enrolled in an ongoing screening study at Leonor Mendes de Barros Hospital, S?o Paulo, Brazil, in 2002. Each residual sample was processed according to the Feulgen-thionin method (TriPath Imaging). Ploidy evaluation was performed using the CAS 200 image analysis system and Quantitative DNA Measurement software 3.0 (version 8.1) (Becton Dickinson, San Jose, Califoria, U.S.A.). Cellular ploidy was analyzed from atypical nuclei, and the DNA index was obtained using histograms for interpretation. RESULTS: All chronic cervicitis cases were diploid. Of the CIN 1 cases, 44% were diploid, 12% tetraploid, 32% aneuploid and 12% polyploid (diploid plus tetraploid). CIN 2 lesions were diploid in 60% and aneuploid in 40% of cases, whereas all CIN 3 lesions (100%) were aneuploid. CONCLUSION: The liquid-based cytologic samples proved to be suitable and highly useful for DNA analysis by image cytometry, which was capable of discriminating CIN 3 lesions from CIN 1 and 2 but not CIN 1 from 2 lesions. Aneuploidy was closely associated with CIN 3 lesions.     

Liquid-based cytology and conventional smears compared over two 12-month periods.

BACKGROUND AND OBJECTIVE: Liquid based cytology (LBC) was introduced across the Scottish Cervical Screening Programme in 2003-2004. The objective of this study was to compare in a large cytopathology laboratory the results of cervical samples over two twelve-month periods, 2001-2002, when the great majority of smears were conventional, with 2003-2004, when all were LBC. METHODS: The results of smears in both periods were analysed to give overall reporting profiles, and correlated with results of cervical biopsies. The numbers of patients referred for colposcopy were compared. RESULTS: The percentage of unsatisfactory smears fell from 13.6% to 1.9%. Colposcopic referrals for repeated unsatisfactory smears fell from almost 25% to 0.5%. There was a decrease in overall smear numbers, but despite this there was an increase in the number of smears reported as showing dyskaryosis of any grade. There was an increase in positive predictive value for moderate dyskaryosis and above, from 79.5% to 86.1%. The outcome of biopsies from patients referred with mild dyskaryosis showed no decrease in accuracy of predicting a low grade histological lesion. Workload in the laboratory decreased, due to fewer smears received overall, more rapid primary screening times and fewer multi-slide cases. Primary screening backlogs all but disappeared, and reporting times greatly improved. CONCLUSIONS: Introduction of liquid based cytology led to improvements in unsatisfactory smear rates, with significant benefits to colposcopic referrals and laboratory turnaround times. Pick-up rates of dyskaryosis were maintained, and the positive predictive value of a dyskaryotic smear report was improved.     

The effect of lubricant contamination on ThinPrep® (Cytyc) cervical cytology liquid-based preparations

Objectives:  To assess the extent of lubricant use by smear-takers and the effect of lubricant contamination of ThinPrep^® processed cervical cytology samples.
Methods:  All primary care smear-takers were sent a questionnaire on lubricant type and frequency of use. Fifty cervical cytology samples were then contaminated with incremental amounts of K-Y^® jelly, 50 samples contaminated with incremental amounts of Aquagel^® and ten non-contaminated vials were processed using the ThinPrep^® T2000 processor followed by Papanicolaou staining. The morphological appearances of lubricant contamination were described microscopically and formal cell counts performed on all slides.
Results:  Seventy of 94 (74.5%) primary care smear-takers indicated lubricant use of whom 9/70 (12.8%) used Aquagel^® and 61/70 (87.2%) used K-Y^® jelly. K-Y^® jelly appeared as mucoid blue deposits in the slide background whereas Aquagel^® appeared as pink stringy background material. Cell counting showed a significant difference between Aquagel^® and K-Y^® jelly contaminated slides compared to the original non-contaminated preparations for all fields and the average fields ( P  < 0.001) with a significantly higher count for the original non-contaminated slides than the lubricant contaminated groups.
Conclusion:  Lubricant contamination of ThinPrep^® cervical cytology samples may result in reduced cellularity of the subsequent slide. This study provides evidence-based data to support British Society for Clinical Cytology recommendations for no lubricant use when taking cervical samples.     

Diagnostic accuracy of liquid‐based endometrial cytology in the evaluation of endometrial pathology in postmenopausal women

C. Remondi, F. Sesti, E. Bonanno, A. Pietropolli and E. Piccione
Diagnostic accuracy of liquid‐based endometrial cytology cytology in the evaluation of endometrial pathology in postmenopausal women Objective: The aim of this study was to compare liquid‐based endometrial cytology with hysteroscopy and endometrial biopsy regarding its diagnostic accuracy in a series of postmenopausal women with abnormal uterine bleeding (AUB) or asymptomatic women with thickened endometrium assessed by transvaginal ultrasound as a screening procedure. Methods: Inclusion criteria were: menopausal status; the presence of AUB and/or thickened endometrium assessed by ultrasound (cut‐off 4 mm); a normal Papanicolaou (Pap) smear; and no adnexal pathology at ultrasound. Exclusion criteria were: previous endometrial pathology; and previous operative hysteroscopy. Of 768 postmenopausal women referred to our general gynaecology clinics, 121 fulfilled the inclusion criteria and were recruited to the trial. Twenty‐one refused to participate. Cytological sampling was carried out by brushing the uterine cavity using the Endoflower device with no cervical dilation and the vial was processed using a ThinPrep® 2000 automated slide processor. The slides were stained using a Pap method. Results: In 98 cases with histological biopsies, endometrial cytology detected five cases of endometrial carcinoma, 10 of atypical hyperplasia and 47 of non‐atypical hyperplasia; 36 cases were negative. In two cases cytology was inadequate because of uterine cervical stenosis. Taking atypical hyperplasia or worse as a positive test and outcome, the diagnostic accuracy of the endometrial cytology was 93.5%, with a sensitivity of 92% and specificity of 95%, a positive predictive value of 73% and a negative predictive value of 99%. All the carcinomas were detected by cytology. Only 42% of women with a positive diagnosis were symptomatic. The cytological sampling was well tolerated by all patients. No complication was registered. Conclusions: Liquid‐based endometrial cytology can be considered an useful diagnostic method in the detection of endometrial pathology as a first‐line approach, particularly if associated with transvaginal ultrasound.     

薄层液基细胞学检查在宫颈普查中应用的临床分析

目的：评价薄层液基细胞学检查在宫颈普查中应用的临床价值。方法：选择经薄层液基细胞学门诊普查妇女520例,其中经TCT检查结果提示ASCUS以上的妇女76例,均进一步采取阴道镜下宫颈活检病理检查,将TCT检查结果与阴道镜下宫颈活检病理检查结果对比分析。结果：TCT检查结果具有较高的检出率及符合率,HSIL组、SCC组与LSIL组符合率比较,差异具有统计学意义（P〈0.05）。结论：TCT检查作为妇科宫颈普查的方法,具有检出率及符合率高的优点;检查结果为HSIL或SCC时,应引起临床极高度重视。     

Impact of liquid-based gynecologic cytology on an HIV-positive population

OBJECTIVE: To examine the imprint of liquid-based technologies for cervicovaginal cytology on HIV-positive women, who are at high risk for cervical intraepithelial neoplasia. STUDY DESIGN: We performed a retrospective search of the cytopathology files of Johns Hopkins Hospital for the cervicovaginal cytology of HIV-positive women to examine the effect of liquid-based technology on this population. RESULTS: Significant intraepithelial lesions (SILs) (low grade SIL or greater) were identified in 24% of the conventional smears and 23% of the liquid-based cytology. Atypical squamous cells of undetermined significance (ASCUS)/atypical glandular cells of undetermined significance was diagnosed in 15% of the conventional smears and 9% of the liquid-based preparations (P = .02). In patients with ASCUS diagnoses and tissue follow-up within 7 months, significant SILs were identified in 29% with conventional smears and in 65% with liquid-based cytology. CONCLUSION: There was no statistically significant difference in the rate of SILs between conventional smears and liquid-based cervicovaginal preparations in HIV-positive women. The diagnosis of ASCUS on liquid-based cytology may have an increased likelihood of representing a significant SIL in comparison to conventional smears. For the high-risk, HIV-positive population, immediate colposcopy and biopsy may be warranted following ASCUS diagnoses on liquid-based cytology.     

P-cadherin expression in glandular lesions of the uterine cervix detected by liquid-based cytology

OBJECTIVE: To study P-cadherin aberrant expression as a possible marker for cervical adenocarcinomas in cytological samples. METHODS: We studied P-cadherin immunoexpression in liquid-based cervical cytology samples of biopsy-proven cervical lesions. RESULTS: We found a statistically significant correlation between P-cadherin expression and a cytological diagnosis of malignancy, either glandular or squamous (P < 0.0001). Twenty-two of 33 malignant cases showed P-cadherin membrane staining. None of the 30 benign cases tested showed membrane staining, but three of them displayed an aberrant nuclear P-cadherin expression. CONCLUSIONS: We concluded that P-cadherin can be used to discriminate between malignant and benign cervical cytological specimens, but not to discriminate glandular from squamous lesions.     

Factors contributing to false‐negative and potential false‐negative cytology reports in SurePath™ liquid‐based cervical cytology

N. Gupta, D. John, N. Dudding, J. Crossley and J. H. F. Smith
Factors contributing to false‐negative and potential false‐negative cytology reports in SurePath ? liquid‐based cervical cytology Objectives: The characteristics of false‐negative conventional cervical cytology smears have been well documented, but there is limited literature available for liquid‐based cytology (LBC), especially SurePath? samples. We aimed to assess the characteristics of false‐negative SurePath LBC samples. Methods: Over a period of 5 years, an audit of false‐negative reports in SurePath cervical cytology was undertaken. In a workload of 183, 112 samples, 481 (0.3%) false negatives were identified using two routes: those detected by routine laboratory internal quality control (rapid pre‐screening) (n = 463) and those reported as normal (true false negatives) with concurrent high‐grade cervical histology (n = 18). Ninety‐five false‐negative cases with a subsequent biopsy reported as at least cervical intraepithelial neoplasia grade 2 (CIN2+) were reviewed for a number of different cytomorphological features. Results: Of 95 samples with subsequent CIN2+, 30.5% predominately contained microbiopsies/hyperchromatic crowded cell groups (HCGs), 27.3% sparse dyskarytotic cells, 4.2% pale cell dyskaryosis, 6.3% small dyskaryotic cells; 3.2% were misinterpreted cells, 8.4% contained other distracting cells, 7.4% were low contrast, 5.3% were unexplained and 7.4% were true negatives. The mean number of microbiopsies/HCGs in that category was 4.6. The mean number of abnormal cells in the sparse dyskaryotic cell category was 13.8. Conclusions: Microbiopsies/HCGs were the commonest reason for false negatives. They were usually present in sufficient numbers to be detected but interpretation could be problematic. Dispersed single abnormal cells were usually not identified because of their scarcity or the presence of distracters.