The number of dyskaryotic cells on an initial ThinPrep® cervical sample showing mild dyskaryosis has predictive value

OBJECTIVES: Recent National Health Service Cervical Screening Programme (NHSCSP) guidelines suggest referral for colposcopy following an initial result of mild dyskaryosis. The aim of this study was to investigate if the number of dyskaryotic cells counted on an initial ThinPrep cervical sample showing mild dyskaryosis has predictive value. METHODS: Cases of mild dyskaryosis on ThinPrep cervical samples from 2002 were retrieved from the cytology department records of St Luke's Hospital. A total of 123 sequential cases with a first-time result of mild dyskaryosis on ThinPrep slides with follow-up cytology available in the same institution were identified. While blinded to outcome, the number of dyskaryotic cells was counted in each case. Follow-up colposcopy/histology information was retrieved where indicated. The number of dyskaryotic cells counted on each slide was collated with outcome data. RESULTS: Of the 123 cases, six women were lost to follow-up. Seventy-three had a negative outcome, 27 had a low-grade outcome and 17 had a high-grade outcome. Only one of 17 high-grade outcome cases had < or = 15 dyskaryotic cells on the initial slide. The distribution of women with a negative/low-grade outcome and those with a high-grade outcome with >15 and < or = 15 dyskaryotic cells on the initial slide was tested using a chi-square test (P = 0.008). The negative predictive value for a high-grade outcome when < or = 15 dyskaryotic cells were present on the initial slide was 97.7%. CONCLUSION: The number of dyskaryotic cells on ThinPrep slides showing mild cervical dyskaryosis has predictive value. The number of dyskaryotic cells may be used to select women suitable for cytological rather than colposcopic follow-up.     

Do borderline nuclear changes in gynaecological cytlogy constitute a reliable reporting category?

Fourteen laboratories participated in a national slide exchange study to investigate whether borderline nuclear changes (BNC) constitute a reliable reporting category. Slides were submitted by participating laboratories, having achieved a 100% intralaboratory consensus at the primary screener, checker, and medical levels. Sets of seven slides were examined in laboratories for 1 week, and exchanges were undertaken over a 6-month period. Each laboratory was requested to submit three consensus opinions on each slide at the primary screener, checker, and medical levels.
Response patterns for submitted slides achieving a reporting category consensus at the 50 and 80% consensus levels indicated that negative, BNC, and mild dyskaryosis are distinct and comparable categories. Similarly, the two subcategories of BNC with or without human papillomavirus (HPV) are nearly as distinct as the overall BNC category.
The percentage of submitted slides achieving consensus at consensus levels between 50 and 80% produced variable findings with regard to the practical success of the main reporting categories. The negative category was reasonably successful, whereas mild dyskaryosis was consistently poor. Borderline nuclear changes were successful at the 50% consensus level but showed a rapid decline by the 65% consensus level. The reason(s) for this remains speculative but indicates a possible potential of BNC to work successfully with additional training and education.
Reporting practices were not consistent among the laboratories and differences were identified between medical and nonmedical staff. A high use of the BNC category was noted in slides that failed to achieve consensus. A national study assessing all grades of abnormalities would appear essential.     

The evaluation of human papillomavirus genotyping in cervical liquid-based cytology specimens; using the Roche Linear Array HPV genotyping assay

Objective:  To ascertain the usefulness of the Roche Linear Array human papillomavirus (HPV) genotyping assay for assessing HPV genotypes in liquid-based cytology (LBC) samples and to evaluate this methodology within a cytopathology laboratory. These tests are of importance as persistent infection with high-risk HPV genotypes is considered a causal factor in the development of cervical cancer.
Methods:  A total of 175 cervical LBC samples were tested using the Roche Linear Array HPV genotyping test. The suitability of the assay use in routine cytopathology laboratory was considered. HPV genotypes were matched to the cervical cytology results, which included negative, borderline nuclear abnormalities, mild, moderate and severe dyskaryosis.
Results:  The assay could be applied to screening samples with the combined result available at the reporting stage. There were no test failures. All samples used after cytological analysis had sufficient DNA for testing. The results were reproducible and easily read and there was concordance of results between biomedical scientists. The results of the assay showed co-infection with multiple HPV genotypes was common in both high-grade and low-grade cytology samples. The percentage of HPV+ samples in the normal cytology samples (although in this grouping the number of samples was low) was 37%. In the cytology samples reported as severe dyskaryosis the HPV genotypes most commonly found were HPV16 and HPV51.
Conclusion:  The assay was able to detect multiple HPV infection with a wide range of genotypes in LBC samples sent for routine cytological analysis. It would be suitable for use in a cytopathology laboratory. The results of the assay show that the genotype profile has some variation from other geographical regions, and more work is needed to determine population prevalence, to ascertain the impact of the HPV vaccine, to evaluate test for cure and HPV triage management.     

Using a quality control approach to define an 'adequately cellular' liquid-based cervical cytology specimen

Objective:  To define a minimum acceptable total squamous cellularity for (ThinPrep^®) liquid-based cervical cytology (LBC) specimens using quality control techniques.
Methods:  Two hundred LBC preparations were made containing varying numbers (<200) of severely dyskaryotic squamous cells and with varying total cellularities.
Results:  Ninety-eight per cent of the LBC preparations that were missed by one or more of three cytoscreeners had fewer than 16 abnormal objects (single dyskaryotic cells or clumps of cells) and 87 dyskaryotic cells. The minimum ratio of dyskaryotic to total squamous cells that, in a preparation of 5000 squamous cells has a probability of at least 0.98 that 87 or more dyskaryotic cells will be present is 1 : 47. Twenty-three preparations diagnosed as abnormal had ratios of dyskaryotic to total squamous cells of between 1 : 2.5 and 1 : 4596. There is thus no feasible minimum acceptable squamous cellularity that will give an acceptable probability of detection of all specimen vials containing abnormal cells in the observed proportions.
Conclusions:  It is suggested that the minimum acceptable cellularity for LBC specimens is set pragmatically by the screening programme to give a feasible percentage of repeat tests.     

P-9A COMPARISON OF THE REPORTING MORPHOLOGICAL FEATURES OF GLANDULAR NEOPLASIA FOR CONVENTIONAL AND LIQUID BASED CYTOLOGY FOR CERVICAL SAMPLES

Cervical cancer accounts for approximately 15% of cancer diagnosed in women worldwide with up to 190 000 deaths per annum. One of the major causes of cervical cancer is the infection of human papillomavirus (HPV), a DNA virus. This virus is epidermotropic; there are over 75 subtypes and subtypes 16, 18, 31 and 33 are associated with cervical intraepithelial neoplasia (CIN) and carcinomas. Since the start of the cervical screening in mid 1960s, the cervical cancer rate has decreased. There are two techniques used for slide preparation and staining: conventional cytology and liquid based cytology (LBC). Due to the differences in sample collection and preparation, certain aspects of cell morphology, architecture and patterns will present differently from each other on the slide. The study was conducted in a County Hospital. Twenty conventional slides and eight LBC slides already reported as ? Glandular neoplasia were reviewed and assessed with regards to their morphological features. Moreover, conventional slides were compared with LBC slides to determine the differences in their cell morphology, sensitivity and specificity. Furthermore, a semi-quantitative method was used and also true-positive and false-positive rates were evaluated using positive predictive value (PPV). The findings indicated that despite the differences in cell morphology there are many similarities between the two techniques. The study also showed that it was difficult to distinguish between abnormal glandular cells and abnormal squamous cells, which may end in a false positive result and over reporting of glandular neoplasia. Finally, it showed that LBC slides were easier to screen and also had a higher positive predictive value (PPV) resulting in higher sensitivity and specificity. In conclusion, the LBC technique is more accurate and conversion to this technique is the positive step in the screening program.     

O-13ENDOMETRIAL CARCINOMA DETECTED WITH SUREPATH LIQUID BASED CERVICAL CYTOLOGY: COMPARISON WITH CONVENTIONAL CERVICAL CYTOLOGY

Liquid based cytology (LBC) has improved cell visualization and preservation in cervical cytology. There has been a reduction in inadequate rate and some data to suggest an increase in sensitivity for dyskaryosis. Training for LBC has focused on differences in distribution of abnormal cells, but in most cases the morphological appearance of the dyskaryotic cells themselves is similar to that seen in conventional cytology. We are describing a new presentation of dyskaryosis which may be a cause of false negative cytology. We have referred to this as 'Bland dyskaryosis' because cells appear deceptively bland on low power examination, and can be misinterpreted as metaplastic or endocervical cells. Bland dyskaryosis cells are seen in groups. The architecture of the group is very disorganized, and adjacent cells show variation in size. Cells have a high nuclear/cytoplasmic ratio and smooth nuclear membranes. Chromatin is finely granular and evenly distributed. This is an unusual presentation of high-grade dyskaryosis and we feel that there is a learning curve in laboratories converting to liquid based cytology. The spectrum of appearances of squamous dyskaryosis needs to be delineated to allow further increases in sensitivity for dyskaryosis.     

P-24MUCINOUS ASCITES - AN APPROACH TO CYTOLOGICAL CLASSIFICATION

Objective:  Recent national guidelines (NHSCSP Document 20) recommend the referral of patients having the first occurrence of mild dyskaryosis. We evaluated the usefulness of this guideline and determined the positive predictive value (PPV) of conventional smears (CS) and ThinPrep samples (TP) reported as the first occurrence of mild dyskaryosis.
Methods:  This was a retrospective study where we looked at the cases of mild dyskaryosis from January'05 to June'05 received at our laboratory. Of these, the cases of mild dyskaryosis at the first instance were only taken into consideration. Histological diagnosis of these cases where available were retrieved from the laboratory database and were correlated with the cytological findings.
Results:  There were 1016 cases, which were reported as mild dyskaryosis. Out of them, 51.1% (519 cases) were first report of mild dyskaryosis: 61.8% (321 cases) and 38.2% (198 cases) were CS and TP respectively. Of these, 181 CS (56.4%) and 120 TP (60.6%) had a histological follow up. The results showed that 54.1% CS and 56.7% TP had a low-grade outcome, 26.0% CS and 25.8% TP had a high-grade outcome and 19.9% CS and 17.5% TP had a normal outcome. The PPV of mild dyskaryosis for CIN1 or worse result was 53.0% and 50.0% in CS and TP respectively. The PPV of mild dyskaryosis for CIN1 only was 27.1% and 24.2% in CS and TP respectively.
Discussion:  The difference in PPV for both systems is statistically insignificant. This result endorses usefulness of colposcopic referral after the first report of mild dyskaryosis.     

Proposed Sheffield quantitative criteria in cervical cytology to assist the grading of squamous cell dyskaryosis, as the British Society for Clinical Cytology definitions require amendment

OBJECTIVE: In 1986, the British Society for Clinical Cytology (BSCC) published quantitative criteria to assist diagnosis in a three-tier grading system of squamous cell dyskaryosis. In dyskaryotic cells, area nuclear to cytoplasmic (NC) ratios below 50%, between 50% and 66% and over 66% were defined as equating with mild, moderate and severe grades respectively. Following the Terminology Conference in 2002, however, the BSCC recommended on their website that the three-tier model should be replaced by a new two-tier system of low- and high-grade squamous abnormalities. The latter broadly equate with the two-grade Bethesda System (TBS) for reporting squamous intraepithelial lesions. The purpose of this study was to assess the accuracy and reproducibility of the BSCC three-tier quantitative definitions, to investigate if they were applicable to liquid-based cytology (LBC) and to see how they related to the proposed new two-tier BSCC system. METHODS: Quantitative image analysis was undertaken on illustrations from the 1986 BSCC terminology publication and on microscope slides from external quality assessment and Cytology Training Centre teaching sets. RESULTS: Analysis of mean NC ratios showed that mild, moderate and severe dyskaryosis exist as statistically different populations. Overlap of NC ratio ranges, however, limits their practical application in the three-tier model, although interestingly no overlap was noted between mild and severe dyskaryosis. No grade of dyskaryosis had a mean area NC ratio over 50%, indicating that the BSCC quantitative definitions are incorrect. The mean diameter NC ratios for mild, moderate and severe dyskaryosis were found to be 40%, 49% and 66% respectively. Accordingly it is possible that those reporting cervical cytology could be interpreting the BSCC NC ratios as meaning diameter rather than area. Amalgamation of the three-tier results into the proposed two-tier model shows that the resulting mean NC area and diameter ratios identify statistically different low- and high-grade populations. The reduced degree of overlap, however, of NC ratio ranges in the two-tier model implies that NC ratios could have a useful practical role in the separation of the low- and high-grade categories. The two categories were reasonably well separated by mean area and diameter NC ratios of 25% and 50% respectively. A two-tier model combining mild with moderate rather than severe dyskaryosis was found to be a statistically valid alternative but gave rise to NC ratios that would be difficult to use in practice. Except for moderate dyskaryosis, no significant differences were identified between the mean NC ratios of either conventional and LBC preparations or LBC preparations using two different commercial methodologies (SurePath and ThinPrep). Differences, however, were noted in area measurements between SurePath and ThinPrep and this has potential implications for classifications (such as TBS) using area comparisons as their basis. In addition, it was found that the increased NC ratio, associated with higher grades of dyskaryosis is more a consequence of progressive cytoplasmic area reduction rather than nuclear area increase. The similar NC ratios of borderline nuclear changes associated with human papilloma virus and mild dyskaryosis support the BSCC proposal that these can be combined to constitute a low-grade category. This study shows that the BSCC area NC ratio criteria of grading squamous cell dyskaryosis require amendment. In addition, this study supports the new BSCC recommendation of low- and high-grade squamous cell categories. CONCLUSIONS: The study proposes Sheffield quantitative criteria to assist the grading of squamous cell abnormalities. Quantitative diameter NC ratio measurements, however, must always be accompanied by detailed assessment of qualitative morphological features and in particular those relating to nuclear chromatin. This is equally relevant to both two- and three-tier models.     

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

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

An audit of the positive predictive value of high-grade dyskaryosis in cervical smears: 2001–2002

The positive predictive value (PPV) of high-grade dyskaryosis for cervical intraepithelial neoplasia grade 2 (CIN2) or worse on histology is published annually for the laboratories in the UK National Health Service Cervical Screening Programme (NHSCSP). The PPV fell in 2001 compared with 2000 for four of the five consultants reporting cervical smears in our laboratory, the greatest fall being from 91.6% to 77.9%. Investigation of the possible reasons for the fall suggested the main cause lay outside the laboratory in the type of biopsy taken at colposcopy. We conclude that biopsy type affects accuracy of PPV calculations. There is variation in collection and submission of KC61 data including PPV across laboratories. This factor needs to be taken into account when publishing and comparing laboratory data for the NHSCSP.     

Comparison of cytology and histology results in English cervical screening laboratories before and after liquid‐based cytology conversion: do the data provide evidence for a single category of high‐grade dyskaryosis?

R. G. Blanks and R. S. Kelly
Comparison of cytology and histology results in English cervical screening laboratories before and after liquid‐based cytology conversion: do the data provide evidence for a single category of high‐grade dyskaryosis? Objective: To determine whether the difference between the positive predictive value (PPV) for cervical intraepithelial neoplasia (CIN) grade 2 or worse (CIN2+) of referral from moderate dyskaryosis and from severe dyskaryosis was reduced after laboratories converted from conventional to liquid‐based cytology (LBC). Furthermore, to explore the cytology/histology agreement after LBC conversion, and to determine post‐LBC whether there was increased support for the use of one single category of high‐grade dyskaryosis (equivalent to high‐grade squamous intraepithelial lesion). Methods: The association between cytology and histology has been examined using annual Korner return data (KC61 returns) collected by laboratories from the English National Health Service cervical screening programme. The study compares return data before and after LBC conversion. Results: The study examined data from 102 laboratories that converted from conventional cytology to LBC. Before conversion the PPV for CIN2+ of severe dyskaryosis was 88% and after increased to 90% (P = 0.003). For moderate dyskaryosis the PPV for CIN2+ increased from 70% to 72% (P = 0.06). The absolute difference of 18% between severe and moderate dyskaryosis was therefore the same pre‐ and post‐LBC conversion. The PPV of mild dyskaryosis for CIN2+ before and after conversion reduced from 23% to 19% (P < 0.001). The agreement between cytology and histology measured using a weighted Kappa statistic increased from 0.52 to 0.60 after conversion to LBC because of small increases in the proportions of severe dyskaryosis or worse with CIN3+ outcomes and mild dyskaryosis with CIN1 or less outcomes. Conclusions: Following LBC conversion there was evidence of a modest increase in the agreement between cytology and histology but no evidence of a change in the absolute difference in PPV for CIN2+ between moderate and severe dyskaryosis. The data support the conclusion that women referred with moderate dyskaryosis will on average have a lower risk of progression to invasive cancer than women referred with severe dyskaryosis. If the data were considered to support the categories of high‐grade dyskaryosis (moderate) and high‐grade dyskaryosis (severe) before LBC conversion then it can be strongly argued that they also support these categories after conversion.     

O‐12BLAND DYSKARYOSIS: A NEW PITFALL IN THINPREP® LIQUID BASED CYTOLOGY

Liquid based cytology (LBC) has improved cell visualization and preservation in cervical cytology. There has been a reduction in inadequate rate and some data to suggest an increase in sensitivity for dyskaryosis. Training for LBC has focused on differences in distribution of abnormal cells, but in most cases the morphological appearance of the dyskaryotic cells themselves is similar to that seen in conventional cytology. We are describing a new presentation of dyskaryosis which may be a cause of false negative cytology. We have referred to this as ‘Bland dyskaryosis’ because cells appear deceptively bland on low power examination, and can be misinterpreted as metaplastic or endocervical cells. Bland dyskaryosis cells are seen in groups. The architecture of the group is very disorganized, and adjacent cells show variation in size. Cells have a high nuclear/cytoplasmic ratio and smooth nuclear membranes. Chromatin is finely granular and evenly distributed. This is an unusual presentation of high‐grade dyskaryosis and we feel that there is a learning curve in laboratories converting to liquid based cytology. The spectrum of appearances of squamous dyskaryosis needs to be delineated to allow further increases in sensitivity for dyskaryosis.     

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.     

P-8THE LOCAL IMMUNE RESPONSE TO LOW-GRADE CIN – ALTERATIONS IN T-CELL AND MACROPHAGE SUBSETS

Objective:  The introduction of Liquid Based Technology (LBC) offers numerous advantages for cervical screening including the facility to make additional preparations after the sample has been reported. Could this additional preparation be used effectively for immunocytochemical (ICC) staining for p16? The aim of this study was to establish working techniques, a scoring system and assess the suitability of p16 for use in diagnostically difficult cases.
Study design:  A working technique for two commercially available antibodies, DakoCytomation Cintec p16INK4a and Vision Biosystems Novocastra p16 was established and applied to three groups of control samples, consisting of negative, borderline and dyskaryotic cases. All dyskaryotic cases were biopsy confirmed. The results obtained were used to formulate a scoring system (0–9), based on the percentage of positive cells and intensity of stain, which could then be applied to test cases. This group of test cases consisted of diagnostically difficult samples, which had been discussed or reviewed in the laboratory.
Results:  The results showed that p16 could aid in the diagnosis of difficult cases and should be assessed together with the original Papanicalaou stained slide to identify the cells in question. The scoring system with a cut off score of 4 for a positive result proved significant.
Conclusion:  Use of p16 in a routine laboratory could help further reduce false positive or negative results thus improving the service offered.     

Posters. P11 Positive predictive values for high and low‐grade cytological abnormalities as surrogates for specificity and sensitivity

Introduction Positive predictive value (PPV), measuring the percentage of moderate dyskaryosis or worse confirmed as CIN2 or worse, is used as a measure of accuracy in cervical screening. However, it relates more to specificity than sensitivity because the denominator includes false positives rather than false negatives. Low values reflect over‐reporting of high‐grade dyskaryosis but high values may reflect under‐reporting. Sensitivity is impossible to measure from correlation of cytology with outcome because women with negative cytology are rarely referred for colposcopy. Rates of CIN3 resulting from referrals for low‐grade cytology may be used as a surrogate for sensitivity, as high values may reflect under‐reporting (ref). Study design Outcome of colposcopy referrals was monitored during a period of 4 years, using a fail‐safe database. Results PPV at Guy's & St Thomas rose from 54% in 1998/1999 to 69% in 2001/2002. The former was below the NHSCSP recommended range. During the same period of time CIN1 rates for moderate dyskaryosis fell from 37% to 24%, reflecting the main source of discrepancy. While specificity increased (as reflected by increasing PPV) sensitivity remained constant in that CIN3 rates for mild dyskaryosis and borderline remained below 6%: average rates in England have fallen over the last 3 years and were 7.4% in 2000/2001 (ref). CIN2 rates for mild dyskaryosis also remained constant at 11% to 12%. Conclusion Correlation of biopsy results with high‐ and low‐grade cytological abnormalities is a useful method of monitoring accuracy of cytology reporting, and can be used to measure over‐ and under‐reporting as surrogates for specificity and sensitivity.     

Inadequate cervical smears: results of an educational slide exchange scheme

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

Rapid Cervical Cytology Screening

2030 Papanicolaou-stained cervical smears were submitted for rapid screening prior to routine screening; 30 seconds were allowed for each slide, and those thought to be abnormal were identified. The results were compared with those of conventional screening. All severe and moderately dyskaryotic cases were detected by the rapid technique, as were the majority of mild dyskaryosis and borderline cases. When a laboratory has a backlog it may be worth rapid-screening all slides in addition to routine screening, so that patients most at risk can receive prompt treatment.     

Decrease in numbers of glandular cell groups in post-LLETZ liquid-based cytology preparations

Objective:  Large loop excision of the transformation zone (LLETZ) has become standard of care in the management of cervical squamous neoplasia and with cone biopsy glandular intraepithelial neoplasia. Controversy remains about the long-term effects of this traumatic procedure. The aim of this study was to count and compare the number of endocervical glandular cell groups in pre- and post-LLETZ cervical preparations using liquid-based cytology to establish a cyto-morphological correlate of destruction of the transformation zone.
Methods:  The cytology/histology correlation audit records of the Cytopathology Department of St Luke's Hospital in 2003 and early 2004 were used to select patients with a cytological diagnosis of high grade dyskaryosis followed by LLETZ. Only those cases with post-LLETZ cytological follow-up were selected. Cases using conventional smears were excluded. One hundred and twenty slides (60 pairs of slides) in total were retrieved. The cases underwent review and all groups of >3 glandular cells in each slide were counted by AM while blinded as to whether smears were pre- or post-LLETZ. Medians were compared using a Mann–Whitney U -test.
Results:  The median number of groups of endocervical glandular cells of the pre-treatment group was 5.5 and of the post-treatment group was 2.0. There were significantly fewer endocervical glandular cell groups in the post-LLETZ population ( P  = 0.03).
Conclusions:  The number of endocervical glandular groups in cervical cytological preparations decreases significantly following LLETZ procedure. This suggests that cytological follow-up may not be as useful in glandular neoplasia cases. Few or absent glandular cell groups in post-LLETZ preparations may have implications for adequacy assessment.     

Characteristics of high grade dyskaryotic cervical smears likely to be missed on rapid rescreening

OBJECTIVE: To determine if there is a type of high grade dyskaryotic cervical smear that is likely to be missed on rapid rescreening. STUDY DESIGN: Fifty high grade dyskaryotic smears that had originally been incorrectly reported as negative (FN) were admixed with 100 true negative smears. Each smear in the set was rapidly reviewed at least 40 times. The FN smears that were picked out on > 50% of screenings were compared with those that were passed as unremarkable on > 50% of screenings for features of the dyskaryotic cell population. RESULTS: Significant differences between the two types of FN smear were present in five aspects of the dyskaryotic cell population. A FN smear is more likely to be missed on rapid rescreening than to be selected for review if it has few dyskaryotic cells; if the dyskaryotic cells are small, with pale nuclei; and if they are scattered singly rather than in groups or syncytia. CONCLUSION: A type of severely dyskaryotic smear is likely to evade rapid rescreening as well as routine screening. This suggests that even when rapid rescreening is used as a quality assurance measure, the "zero-error standard" is unlikely to be attained.