Experience with a thin-layer,liquid-based cervical cytologic screening method

OBJECTIVE: To assess the utility of a thin-layer cytology system for cervicovaginal screening in clinical practice. STUDY DESIGN: Twenty-five hundred cervicovaginal split samples were processed with the traditional direct smearing method and with the ThinPrep Pap Test (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) method and evaluated according to the Bethesda system, focusing mainly on the cytomorphologic features. RESULTS: The ThinPrep Pap Test yielded improved specimen adequacy and an increased detection rate of squamous abnormalities, which resulted in a decrease in the ASCUS/SIL ratio. Moreover, the thin-layer system provided adequate material for concomitant HPV testing, mainly in the LSIL and the ASCUS favor SIL cases, with satisfactory results, as well as for cell block preparations in a few selected cases that presented diagnostic difficulties. Furthermore, the morphologic features of the LSIL cases were virtually identical on both preparations, while in the HSIL cases, distinct features were noted on ThinPrep. CONCLUSION: The ThinPrep Pap Test is significantly more effective than the conventional smear in clinical practice. However, training and experience are necessary to take full advantage of this promising new technology.     

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

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

Higher diagnostic accuracy with the ThinPrep method in a simulated intraoperative environment

Objective:  To compare the accuracy of intraoperative fine needle aspiration cytology samples prepared by the ThinPrep method to conventional cytological methods. Specimen adequacy and turn around time (TAT) were also assessed.
Methods:  Fifty consecutive fresh tumours submitted for histological analysis were aspirated and each prepared as follows: (i) direct smear with H&E stain, (ii) direct smear with Pap stain, (iii) ThinPrep slide with H&E stain, and (iv) ThinPrep slide with Pap stain. The slides were randomly distributed to three cytopathologists for interpretation. The quality of the preparation, the diagnosis and the time needed for interpretation were recorded.
Results:  Accuracy was measured as the percentage of absolute agreement between the cytological and the histopathological diagnoses of the lesions. Histologically, there were 43 malignant and six benign lesions and one atypical lipoma. The TAT began when the slides/cytolyte specimens arrived at the lab and ended with the pathologist's diagnosis.
Conclusions:  In terms of accuracy and specimen adequacy, ThinPrep slides with Pap stain is the best procedure. This advantage however is offset by the longer testing time.     

A new look at cervical cytology. ThinPrep multicenter trial results.

The objective of this study was to compare the sensitivity of a new test method with the smear method for detection of neoplasia of the uterine cervix. The new procedure, the ThinPrep process, is an automated, fluid-based technique for the collection and preparation of exfoliated and aspirated cytologic specimens. A single sample from each patient was split and prepared both with the smear and test methods. The diagnostic results from the two slides were compared in this blind study. Among a total of 2,655 patients, diagnoses concurred in 92% of cases and were within one diagnostic level of each other 98% of the time. The ThinPrep method facilitated the detection of more low-grade lesions (P less than .001, McNemar's test). In addition, the test method decreased the number of ambiguous interpretations. The ThinPrep method appears to improve the cervical cytologic smear quality by the harvest of a random and reproducible sample, with a reduction in artifacts. The new method improves the sensitivity of the cervical cytologic screening test.     

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

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

Does liquid-based technology really improve detection of cervical neoplasia? A prospective, randomized trial comparing the ThinPrep Pap Test with the conventional Pap Test, including follow-up of HSIL cases

OBJECTIVE: To compare the sensitivity, specificity and specimen adequacy of the ThinPrep Pap Test (TP) with the conventional Pap Test (CV) in a low-risk population with subsequent follow-up of HSIL cases. STUDY DESIGN: A prospective, randomized, controlled design was chosen to compare the TP with CV. Cytologic diagnosis and specimen adequacy were evaluated and compared with histology data in high grade squamous intraepithelial lesion (HSIL) cases. Fifteen gynecologists in private practice, all trained in colposcopy, participated in the trial. Cytologic diagnosis, specimen adequacy and follow-up of the cytologic HSIL cases were compared in the two groups. In total, 1,999 patients were included, 997 in the TP group and 1,002 in the CV group. Randomization assignments were designated on cytology case report forms, which were placed in sealed envelopes. Each envelope had a sequential randomization number on the outside to allow tracking and authentication of randomization assignments. RESULTS: Comparison of results between CVs and TPs revealed no statistically significant differences in all diagnostic categories, ranging from "within normal limits" to HSIL. Specimen adequacy, however, was superior with CVs (P < .001). The cytologic diagnosis of HSIL correlated with the histologic diagnosis in 91% of the TP group and 100% of the CV group. CONCLUSION: Because there was no statistically significant difference in sensitivity and specificity of the two techniques, improved detection of cervical abnormalities and better specimen adequacy might not be a consequence of utilizing liquid-based preparations but of a better sampling technique. Removing mucus and cellular debris from the cervical surface with a cellulose swab before sampling cells with a proper sampling device results in the same sensitivity and specimen adequacy and is much less expensive than the liquid-based technique.     

Bile duct brushings cytology – improving sensitivity of diagnosis using the ThinPrep® technique: a review of 113 cases

OBJECTIVE: Common bile duct (CBD) brushings have been recognized as a technique of moderate sensitivity and high specificity in identifying carcinoma of the ampulla and pancreatico-biliary regions. This study evaluated the increase in sensitivity of this technique using the ThinPrep technique of specimen preparation when compared with conventional cytology smears. METHODS: A total of 113 bile duct brushings were included in the study (38 conventional smears and 75 slides prepared using the ThinPrep technique). All slides were reviewed by one cytologist. Five categories of reporting were used: inadequate, negative, atypia, suspicious and malignant. RESULTS: The inadequate category of reporting disappeared in the ThinPrep group with improved specimen fixation and preparation and hence reduced artefact. Sensitivity of diagnosis of malignancy increased from 39% in conventional smears to 53% in the ThinPrep group. Specificity, positive and negative predictive values and accuracy were 100%, 100%, 60% and 68% for conventional smears and were 100%, 100%, 60% and 72%, respectively, for ThinPrep specimens. CONCLUSIONS: ThinPrep technique was associated with increased sensitivity of diagnosis, in part due to improved specimen fixation and reduced artefact. Cytology of bile duct brushings is an important diagnostic tool for sites from which it can be difficult to obtain a histology biopsy. It may therefore provide the only opportunity for tissue diagnosis of carcinoma from these sites, hence the importance of optimizing sensitivity.     

Diagnostic value of fine needle aspirates processed by ThinPrep® for the assessment of axillary lymph node status in patients with invasive carcinoma of the breast

X. Jing, E. Wey and C. W. Michael Diagnostic value of fine needle aspirates processed by ThinPrep® for the assessment of axillary lymph node status in patients with invasive carcinoma of the breast Objective: To evaluate the utility of ThinPrep® as an optional specimen processing method for the detection of axillary lymph node metastasis of invasive breast carcinoma. Methods: A computer SNOMED search from the file at our institution between January 2003 and August 2011 retrieved a total of 209 fine needle aspiration (FNA) specimens of axillary lymph nodes prepared by ThinPrep and followed by axillary lymph node biopsy and/or dissection. Original cytological diagnoses and corresponding histological diagnoses were documented. Using the histological diagnoses as the gold standard, the diagnostic parameters including sensitivity, specificity, positive (PPV) and negative predictive values (NPV) and diagnostic accuracy were calculated. Both cytology and histology slides from cyto‐histologically discrepant cases were reviewed. Results: Out of a total of 209 specimens, 193 (92%) had adequate diagnostic material while the remaining 16 specimens (8%) were inadequate for cytological assessment. The diagnostic specimens included 168 invasive ductal carcinomas (IDC), 15 invasive lobular carcinomas (ILC) and 10 mixed carcinomas (IDC and ILC). Excluding 19 cases with malignant cells on FNA in which no residual tumour was found in fibrotic lymph nodes after neoadjuvant therapy (cytology and histology confirmed on review) ThinPrep detected nodal metastasis with an overall sensitivity of 77.5%, specificity of 100%, PPV of 100% and NPV of 53.7%. Diagnostic accuracy was 82.2%. There was no difference in Bloom–Richardson grade or the number or size of metastases between tumours with true‐positive and false‐negative cytology. Sampling error was the sole factor contributing to cyto‐histological discrepancy. Conclusions: ThinPrep is a good alternative to the conventional smear for cytological assessment of axillary lymph node status in patients with invasive breast carcinoma, particularly when specimens are collected at remote sites or when cytologists are not available for assistance during FNA.     

Sputum cytology for the diagnosis of lung cancer. Comparison of smear and modified cell block methods

OBJECTIVE: To compare the sputum smear cytology and cell block methods for specimen adequacy, cytology quality and diagnostic accuracy in the diagnosis of lung cancer. STUDY DESIGN: We assessed 2,524 sputum specimens from 768 patients. The specimens were prepared as smears and cell blocks for cytopathologic examination between March 1, 1992, and December 31, 1998. The smear and cell block slides were evaluated both separately and together, and the results were compared with radiologic and histopathologic diagnoses. RESULTS: The sensitivity of the smear method was 69.4% and specificity was 99.5%. The sensitivity of the cell block method was 84.4% and specificity, 100%. The sensitivity of the smear and cell block together was 87.6% and specificity, 99.5%. CONCLUSION: The cell block method increases the sensitivity and specificity of sputum cytology, and when smear and cell block slides are evaluated together, sensitivity reaches its highest value. Therefore, application of smear and cell block methods together seems most useful in the diagnosis of lung cancer.     

Thin-layer preparations of dithiothreitol-treated bronchial washing specimens

OBJECTIVE: To evaluate the combined effect of dithiothreitol (DTT) treatment and ThinPrep (TP) (Cytyc Corp, Boxborough, Massachusetts, U.S.A.) processing on bronchial washing specimens. STUDY DESIGN: A total of 431 bronchial washing specimens were initially treated with 0.05% DTT in a 30% methanol solution. After centrifugation, 1 TP slide and 2-4 conventional cytospin or smear preparations (CPs) were prepared. The reports of both preparations were compared in all cases. All 48 abnormal cases and 52 consecutive negative cases were also compared for cellular composition, distribution of the cells, ease of interpretation and overall preparation quality. Screening time was recorded for 20 of the cases. RESULTS: The diagnostic accuracy of one TP slide appeared comparable to that of 2-4 CPs. The TP slide was assessed to be equal or superior in overall quality to CP in 85% of 100 cases of paired specimens. The cleaner background and smaller cellular area of TP slides significantly reduced the screening time. Mucolysis and specimen homogenization were not always optimal, occasionally resulting in uneven subsampling and poorly cellular TPs. However, in general, TP slides were considered superior to CPs in overall quality. CONCLUSION: Improvement in specimen quality and reduced screening time have to be balanced against the high cost of consumables with the TP technique.     

Personal view. Is it reality or an illusion that liquid‐based cytology is better than conventional cervical smears?

Liquid-based cytology (LBC) has been heralded as the way forward for cervical screening, and as the answer to many of its problems. It is already used as a sole method of cell preparation in many private clinics in the UK. It is being used for colposcopy smears in many NHS clinics and is now being piloted for primary screening in three screening centres in England, as well as one in Scotland and one in Wales. LBC has been welcomed as a new technology because it deals with the problem of specimen adequacy at source, removing responsibility for slide preparation and fixation from the clinician or nurse. It provides uniformly well-fixed preparations that are free of inflammatory exudate and blood, and seem easier to screen than conventional smears. There are many articles in the world literature suggesting that LBC is more accurate than conventional screening, and it is thought likely to reduce the number of false negative tests. The main reasons for piloting LBC in the NHS Cervical Screening Programme (NHSCSP) lie in its potential for reducing screening times and for reducing the numbers of repeats for inadequate tests. LBC is expensive in terms of equipment, capital costs, maintenance, consumables, training, technical preparation time, transportation and disposal of liquid media. Its costs could be justified if they were offset by the money saved from reduced screening time and repeat tests, but only if its accuracy in terms of sensitivity and specificity were proven to be equal to or better than conventional cytology. Although that is generally held to be true by the public and medical profession alike, there is very little hard evidence to support it.     

Use of a thin-layer technique in thyroid fine needle aspiration

OBJECTIVE: To investigate the efficacy of the ThinPrep Processor (Cytyc Corporation, Boxborough, Massachusetts, U.S.A) in fine needle aspiration (FNA) of thyroid gland lesions. STUDY DESIGN: This study included 459 thyroid FNA specimens obtained from patients who came to our endocrinology department with various thyroid disorders over 3 years. The cytologic material was prepared using both the conventional and ThinPrep method in the first 2 years (285 cases), while in the last one only the ThinPrep method was used (1 74 cases). The smears were stained using a modified Papanicolaou procedure and May-Grünwald-Giemsa stain. Immunocytochemistry was performed on thin-layer slides using specific monoclonal antibodies when needed. Thin-layer and direct smear diagnoses were compared with the final cytologic or histologic diagnoses, when available. RESULTS: Our cases included 279 adenomatoid nodules, 15 cases of Hashimoto thyroiditis, 45 follicular neoplasms, 14 Hürthle cell tumors, 58 papillary carcinomas and 1 5 anaplastic carcinomas. Thin-layer preparations showed a trend toward a lower proportion of inadequate specimens and a lower false negative rate. Cytomorphologic features showed some differences between the 2 methods. Colloid was less frequently observed on ThinPrep slides, while nuclear detail and micronucleoli were more easily detected with this technique. Moreover, ThinPrep appeared to be the appropriate method for the use of ancillary techniques in suspicious cases. CONCLUSION: Thin-layer cytology improves the diagnostic accuracy of thyroid FNA and offers the possibility of performing new techniques, such as immunocytochemistry, on the same sample in order to detect malignancy as well as the type and origin of thyroid gland neoplasms.     

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.     

A thin-layer,liquid-based pap test for mass screening in an area of China with a high incidence of cervical carcinoma. A cross-sectional,comparative study

OBJECTIVE: To confirm the accuracy of the ThinPrep Pap Test (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) on the basis of histologic diagnosis by biopsy and the detection of human papillomavirus (HPV) DNA in mass screening. STUDY DESIGN: A total of 1,997 women residing in Xiangyuan County, Shanxi Province, P.R.C., an area with a high incidence of cervical carcinoma, were enrolled in this study. We collected exfoliative cervical samples from all subjects into a liquid buffer (Preserv-Cyt [Cytyc]) and utilized for both cytologic screening using the ThinPrep Pap Test and HPV DNA testing. Subsequent colposcopic biopsies were taken on all subjects. All the tests were performed in an independent and blinded fashion. We compared the ThinPrep Pap test with colposcopic biopsy and HPV test. RESULTS: High grade squamous intraepithelial lesions (HSIL) (CIN 2/3) were identified in 74 (3.7%) of 1,993 women adequately assessed, and there were 12 cases of squamous cell carcinoma (SCC). The false negative rate of ThinPrep cytology was 3.2% for biopsy-confirmed CIN 3 and 9.3% for CIN 2. Twenty-seven (87%) of the 31 women with biopsy-confirmed CIN 3 and 12 (100%) of 12 with biopsy-confirmed SCC had a diagnosis of either HSIL or greater abnormalities on ThinPrep cytology. In addition, the HPV DNA detection rates offered a good correlation between cytology and biopsy. CONCLUSION: The ThinPrep Pap performed extremely well in this primary screening trial. We found a good correlation between ThinPrep cytology and colposcopic biopsy on detection of HSIL and SCC; cervical specimens collected in ThinPrep liquid buffer serve as a direct test for HPV as well.     

Performance of a new, liquid-based cervical screening technique in the clinical setting of a large French laboratory

OBJECTIVE: To compare the performance of liquid-based cytology with the CYTO-screen System (SEROA) with that of conventional smears through a secondary analysis of a large database covering the activity of an independent French laboratory during the period 1998-2002. STUDY DESIGN: The study was performed with a retrospective, comparative, historical design on 2 subgroups of women having been screened by gynecologists who switched from conventional smears to the CYTO-screen System in the period 1998-2002. The first cohort population consisted of women who had at least 4 subsequent screening tests over the period with half conventional and half with the CYTO-screen System. A control group consisted of smears collected by gynecologists who fully maintained activity with a conventional method over the same period. The second group consisted of women who had their first screening test performed over the study period by gynecologists who modified their technique. Specimen adequacy, endocervical cell content and epithelial cell abnormality detection rates were compared between the groups. RESULTS: As compared with the conventional smear, the CYTO-screen System showed a reduction in unsatisfactory reports, especially in the second group of first-screened (0.14% versus 1.3%, P < .0001). The rate of atypical squamous cells of undetermined significance increased significantly after the switch to the CYTO-screen System (2.5% versus 1.3%, P = .004) and in the second group of first-screened women (2.05% versus 1.4%, P = .0014), with higher histologic confirmation in both situations. There was a non-significant increase in the detection rates of low and high grade squamous intraepithelial lesions after the switch to the CYTO-screen System and in the second group of first-screened women. CONCLUSION: The CYTO-screen System gives higher-quality specimens and has a higher detection rate for squamous intraepithelial lesions, but that rate was significant only for atypical squamous cells of undetermined significance.     

An Australian trial of ThinPrep: a new cytopreparatory technique

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

Proffered papers 14.00–15.00 Tuesday 16 September 2003

Background  ERCP-directed brush cytology is used to sample lesions of the pancreatic and biliary ducts and the ampulla of Vater. With conventional preparations, the sensitivity and specificity range from 44% to 63% and 80% to 98%, respectively, and increased N : C ratio, nuclear molding and loss of honeycombing are reliable features of malignancy. The performance and morphology of specimens prepared by ThinPrep, a liquid-based cytology technique is mostly unknown.
Methods  The laboratory information system was searched for all cases prepared by ThinPrep. Patient disease classification of benign or malignant was determined by linkage with the provincial cancer registry and was the gold standard against which sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated. True positives and negatives were reviewed to identify predictive cytomorphologic features.
Results  Between 1996 and 2001, there were 149 ThinPrep specimens; 55 (37%) were reported as positive for malignancy and 94 (63%) as negative. Disease was classified as malignant in 86 (58%) patients and benign in 63 (42%). There were 42 false negative, 11 false positive, 52 true negative, and 44 true positive cytology results. Sensitivity was 51.2% (CI; 40.2 : 62.0), specificity 82.5% (CI; 70.5 : 90.6), and PPV and NPV 80.0% (CI; 66.6 : 89) and 55.3% (CI; 44.7 : 65.5), respectively. Cell groups with crowded, enlarged, irregular nuclei and nuclear features of vesicular chromatin and large, multiple irregular nucleoli correlated with malignant disease, while monolayered sheets of uniform columnar cells, regular nuclei and a finely granular chromatin correlated with benign disease.
Conclusions  The performance of ThinPrep brushings from this anatomic site equals conventional preparations. Cytomorphologic features of malignancy are more frequent and pronounced with ThinPrep.     

Cytologic evaluation of conjunctival epithelium using Cytobrush-S: value of slide preparation by ThinPrep technique

Cytologic evaluation of conjunctival epithelium using Cytobrush-S: value of slide preparation by ThinPrep technique
Recent clinical trials have indicated that an automated smear apparatus (ThinPrep process) of sample preparation has great diagnostic sensitivity. In this study, conjunctival brush cytology prepared using the ThinPrep method was applied in ocular surface disorders especially for dry eye status. To assess its diagnostic value in cellular samples, 17 patients with keratoconjunctivitis sicca (KCS) and 10 normal volunteer patients were examined using this technique. Conjunctival cells from normal controls revealed fine chromatin and polyhedral cytoplasm without having keratinized cytoplasm. On the other hand, the cellular samples from KCS revealed increased keratinized cells with pyknotic nuclei. They also contained extremely elongated cells. In KCS patients, the mean number of keratinized cells was significantly higher (34.1 cells/300 cells) than that of the normal control group (0.2 cells/300 cells). In patients with KCS, inflammatory cell counts were also higher than those of normal controls. Conjunctival cytology by means of the ThinPrep method obviously deserves additional trials as an adjunct in the cytology of dry eye states, especially in quantitative ocular evaluation for various ocular lesions.     

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

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

Proffered papers 14.00–15.00 Tuesday 16 September 2003 8 Ampullary,pancreatic and biliary duct exfoliative brush cytology prepared by the thinprep method: performance and morphology

Background ERCP‐directed brush cytology is used to sample lesions of the pancreatic and biliary ducts and the ampulla of Vater. With conventional preparations, the sensitivity and specificity range from 44% to 63% and 80% to 98%, respectively, and increased N : C ratio, nuclear molding and loss of honeycombing are reliable features of malignancy. The performance and morphology of specimens prepared by ThinPrep, a liquid‐based cytology technique is mostly unknown. Methods The laboratory information system was searched for all cases prepared by ThinPrep. Patient disease classification of benign or malignant was determined by linkage with the provincial cancer registry and was the gold standard against which sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated. True positives and negatives were reviewed to identify predictive cytomorphologic features. Results Between 1996 and 2001, there were 149 ThinPrep specimens; 55 (37%) were reported as positive for malignancy and 94 (63%) as negative. Disease was classified as malignant in 86 (58%) patients and benign in 63 (42%). There were 42 false negative, 11 false positive, 52 true negative, and 44 true positive cytology results. Sensitivity was 51.2% (CI; 40.2 : 62.0), specificity 82.5% (CI; 70.5 : 90.6), and PPV and NPV 80.0% (CI; 66.6 : 89) and 55.3% (CI; 44.7 : 65.5), respectively. Cell groups with crowded, enlarged, irregular nuclei and nuclear features of vesicular chromatin and large, multiple irregular nucleoli correlated with malignant disease, while monolayered sheets of uniform columnar cells, regular nuclei and a finely granular chromatin correlated with benign disease. Conclusions The performance of ThinPrep brushings from this anatomic site equals conventional preparations. Cytomorphologic features of malignancy are more frequent and pronounced with ThinPrep.