Comparison of ThinPrep and conventional preparations on fine needle aspiration cytology material

OBJECTIVE: To compare the various cytologic features on ThinPrep 2000 (TP) (Cytyc Corporation, Marlborough, Massachusetts, U.S.A.) and conventional preparation (CP) specimens from fine needle aspiration cytology (FNAC) material by a semiquantitative scoring system. STUDY DESIGN: In this prospective study a total of 71 consecutive cases were included. In each case, two passes were performed. The first pass was used for conventional preparations, with direct smears made and fixed immediately in 95% alcohol for Papanicolaou stain. For TP preparation a second pass produced material for processing in the ThinPrep 2000. The TP and CP slides were studied independently by two observers and representative slides of CP and TP compared for cellularity, background blood and necrotic cell debris, cell architecture, informative background, presence of monolayer cells, and nuclear and cytoplasmic details by a semiquantitative scoring system. Statistical analysis was performed by Wilcoxon's signed rank test on an SPSS program (Chicago, Illinois, U.S.A.). RESULTS: TP preparations contained adequate diagnostic cells in all cases and were tangibly superior to CP preparations concerning monolayer cells, absence of blood and necrosis, and preservation of nuclear and cytoplasmic detail (statistically significant, Wilcoxon's signed rank test, P < .000). CONCLUSION: TP preparations are superior to conventional preparations with regard to clear background, monolayer cell preparation and cell preservation. It is easier and less time consuming to screen and interpret TP preparations because the cells are limited to smaller areas on clear backgrounds, with excellent cellular preservation. However, TP preparations are more expensive than CP and require some experience for interpretation.     

Salivary gland fine needle aspiration using the ThinPrep technique: diagnostic accuracy, cytologic artifacts and pitfalls

OBJECTIVE: To retrospectively assess the diagnostic accuracy, cytologic features and pitfalls of ThinPrep (TP) (Cytyc Corporation, Marlborough, Massachusetts, U.S.A.) versus conventional (smear) preparation (CP) in salivary gland fine needle aspiration biopsies (FNABs) and second, to evaluate the reproducibility of the cytomorphologic criteria used in the evaluation of FNABs prepared by CP versus TP. STUDY DESIGN: All salivary gland fine needle aspiration biopsies (SGFNABs) between January 1996 and June 1999 were retrieved from the cytology files of the University of Michigan Hospital. Histologic correlation was identified when available. Two cytopathologists reevaluated the slides for artifacts, cellular preservation, background material, cellularity, and cytoplasmic and nuclear details. RESULTS: Seventy-four of the 134 (55%) cases identified had histologic follow-up. Fifty (68%) cases were processed by TP and 24 (32%) by CP. FNAB processed by TP and CP correctly identified malignancy in 14 and 9 cases, respectively. There were three (4%) false negative cases. These included two acinic cell carcinomas and one mucoepidermoid carcinoma. There were 37 true negative cases (24 TP and 13 CP) and one false positive case of cellular pleomorphic adenoma (cytologic interpretation, mucoepidermoid carcinoma). All discrepant cases were processed using the TP method. The overall specificity and sensitivity were 98% and 88%, respectively. However, specificity and sensitivity for TP-processed SGFNABs were 96% and 82% as compared to a 100% specificity and sensitivity for CP. Additionally, there were 10 (14%) nondiagnostic cases, 8 of which were processed by TP. Cytologic artifacts associated with TP included diminished/distorted extracellular and stromal elements, cellular shrinkage and tissue fragmentation CONCLUSION: The diagnostic accuracy of TP-processed SGFNABs approaches that of the CP. However, there are several artifacts that may lead to erroneous diagnoses. Additional studies, that depend on real-life clinical samples processed by TP are suggested to modify current diagnostic criteria.     

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.     

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.     

Screening parameters for ThinPrep and conventional gynecologic cytology via automated monitoring

OBJECTIVE: To compare diagnostic discrepancies and screening parameters between conventional (CP) and ThinPrep (TP) (Cytyc Corporation, Boxborough, Massachusetts, U.S.A.) cervicovaginal samples using Pathfinder (Neopath, Redmond, Washington, U.S.A.). STUDY DESIGN: Pathfinder tracked average screening time, percent slide coverage and percent overlap of viewing fields for CP and TP. False negative rate (FNR) was determined by rescreening 10% of random and high-risk negative cases. CP and TP FNR with Pathfinder were compared to control groups without Pathfinder. RESULTS: A total of 46,393 Pathfinder cases were evaluated (43,354 CP, 3,039 TP) as compared to 62,981 without Pathfinder (60,307 CP, 2,674 TP). FNR was calculated for 12,983 negatives. Using Pathfinder resulted in a significant reduction in FNR for CP atypical squamous cells of undetermined significance and atypical glandular cells of undetermined significance cases. No decrease in FNR was observed for CP squamous intraepithelial lesions or for TP cases. TP slides were screened 66 seconds faster on average than CP. With electronic feedback, mean percent slide coverage and percent overlap were similar between CP and TP cases. Without feedback, coverage dropped and overlap increased slightly for both CP and TP. Technologists screened faster with feedback, saving an average of 50 seconds on CP and 41 seconds on TP. CONCLUSION: Pathfinder significantly reduced FNR for CP but not TP. Technologists screened TP significantly faster than CP while maintaining similar coverage and overlap. Pathfinder feedback itself may decrease screening time.     

Increasing diagnostic accuracy with a cell block preparation from thin-layer endometrial cytology: a feasibility study

OBJECTIVE: To investigate (1) the feasibility of preparing cell blocks by inverted filter sedimentation (IFS-CB) from endometrial samplings processed by the ThinPrep (TP) technique (Cytyc Corp., Boxborough, Massachusetts, U.S.A.), and (2) the possibility of increasing the diagnostic accuracy of TP endometrial cytology by examining the tissue architecture as an adjunctive method of detecting endometrial lesions. STUDY DESIGN: Three hundred one endometrial samplings were obtained, using the Endogyn endometrial device (Biogyn S. n.c., Italy), from perimenopausal and postmenopausal women. The endometrial samplings were collected in a vial with liquid fixative for the TP processing. One TP slide was prepared from each case. If adequate material remained in the vial after the TP slide preparation, it was processed for IFS-CB preparation. RESULTS: IFS-CB preparation was processed in 263 cases (87%) with adequate material. Diagnoses on IFS-CB preparations obtained by endometrial sampling matched those of the hysterectomy specimens. The addition of IFS-CB histology to the cytologic diagnosis by TP increased the diagnostic accuracy of endometrial cytology to 96.3% and 100% for benign/atrophic endometrium and adenocarcinoma, respectively (p = 0.39 and 0.46). In hyperplasia without atypia and hyperplasia with atypia, the diagnostic accuracy increased significantly, to 96% and 95.3%, respectively (p = 0.037 and < 0.001). CONCLUSION: This study illustrates the merit of linking TP cytology with direct endometrial sampling, including small tissue fragments and material adequate for IFS-CB preparation. TP cytology provides an accurate cytologic diagnosis and the possibility of IFS-CB preparation, which could be a valuable diagnostic adjunct to TP cytology.     

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.     

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.     

Accuracy of liquid-based Pap tests: comparison of concurrent liquid-based tests and cervical biopsies on 782 women with previously abnormal Pap smears

OBJECTIVE: To evaluate the diagnostic performance of a liquid-based Pap test, the ThinPrep Pap test (TP) (Cytyc Corp., Boxborough, Massachusetts, U.S.A.), by comparing concurrent TP and cervical biopsy results on 782 patients who were referred for colposcopy because of previously abnormal conventional Pap smears (CPs). STUDY DESIGN: The ability of TP diagnoses of atypical cells of undetermined significance (ASC-US) and squamous intraepithelial lesions (SILs) to predict biopsy diagnoses of cervical intraepithelial neoplasia (CIN) was analyzed using chi2 and McNemar tests. RESULTS: The rate of agreement between diagnoses of SIL by TP and CIN by biopsy was 74.7%. ASC-US accounted for 16.0% of TP diagnoses. ASC-US had biopsy diagnoses of CIN 1 in 60% and CIN 2/3 in 12.8% of cases. For TP diagnosis of low grade SIL, biopsy diagnoses of CIN 2/3 were found in 13.5% of cases. For TP diagnoses of ASC-US and higher, the proportions of TP and cervical biopsies in comparable diagnostic categories were statistically significant (p < 0.001), with TP having sensitivity of 89.4% and positive predictive value of 89.7% for the detection of CIN. The false positive rate for TP was 8.1%, but rescreening confirmed the presence of abnormal cells in 51 of 63 (81.0%) cases of ASC-US or higher having negative biopsies. TP had a false negative rate of 8.3% and negative predictive value of 61.3%. Rescreening showed that most (77.6%) of the false negative TP specimens failed to have abnormal cells on the slides. CONCLUSION: For patients having previously detected cervical abnormalities by CP, concurrent TP demonstrated the following: (1) that it has high diagnostic accuracy for SIL, (2) that ASC-US was diagnostically equivalent to LSIL, and (3) that false negative TP for SIL can be attributed primarily to sampling rather than cytotechnologists' screening errors.     

An audit of liquid‐based cervical cytology screening samples (ThinPrep and SurePath) reported as glandular neoplasia

S. A. Thiryayi, J. Marshall and D. N. Rana
An audit of liquid‐based cervical cytology screening samples (ThinPrep and SurePath) reported as glandular neoplasia Objectives: The aims of this study were to assess the number of cases diagnosed as glandular neoplasia (national report code 6) of cervical (6A) and non‐cervical (6B) types on ThinPrep (TP) and SurePath (SP) liquid‐based cytology (LBC) samples and to calculate the positive predictive value (PPV) of these diagnoses for significant glandular and/or squamous pathology for local audit and as a contribution to national data on glandular neoplasia. Methods: A computerized search identified all screening LBC samples reported as glandular neoplasia during the 24‐month period from January 2006 to December 2007. Corresponding histology samples were identified, with a minimum follow‐up period of 6 months for each case. Results: A total of 70 samples, representing 70 patients, were reported as glandular neoplasia, 39 TP (55.7%) and 31 SP (44.3%), with 46 samples (31 TP, 15 SP) reported as 6A and 24 samples (eight TP, 16 SP) as 6B. PPV of glandular neoplasia was calculated for a biopsy diagnosis of cervical glandular intraepithelial neoplasia/adenocarcinoma and/or cervical intraepithelial neoplasia (CIN) 2 or worse. The PPV of 6A was 100% for both TP and SP. The PPV of 6B for adenocarcinoma was 62.5% for TP and 66.7% for SP. The combined PPV for 6A + 6B was 92.3% for TP, 83.3% for SP and 88.4% combined. The overall pick‐up rates for the two methods were significantly different (TP 0.031%, SP 0.052%; P = 0.014). Histology showed only CIN3 with endocervical crypt involvement in nine TP cases and one SP case.     

Comparing the accuracy of ThinPrep Pap tests and conventional Papanicolaou smears on the basis of the histologic diagnosis: a clinical study of women with cervical abnormalities

OBJECTIVE: To confirm that the ThinPrep Pap test (TP) is as effective as or more effective than the conventional Papanicolaou smear (CS) in detecting epithelial cell abnormalities in a population with cervical abnormalities. STUDY DESIGN: In a blinded, split-sample, matched-pair study, a CS was prepared using a cytobrush, and then TP slides were prepared from the remainder of the sample. All slides were evaluated as defined and classified by the Bethesda System. The results of the two cytologic tests were compared in 483 women relative to the histologic diagnoses of subsequent colposcopically directed cervical biopsies in 158 cases. RESULTS: The cytologic diagnoses from the two methods agreed exactly in 91.4% of cases. The comparison between the two cytologic diagnoses with reference to the histologic diagnosis of subsequent colposcopically directed cervical biopsies showed that TP was significantly more specific for diagnosing lesions than was CS. The sensitivity of the two methods was equivalent. CONCLUSION: In a population with cervical abnormalities, TP is more specific than and as effective as CS in detecting cervical epithelial cell abnormalities. TP improved the specificity of disease detection by reducing the atypical squamous cells of undetermined significance category and/or false positive cases.     

Application of ThinPrep Bronchial Brushing Cytology in the Early Diagnosis of Lung Cancer: A Retrospective Study

The majority of lung cancer patients are diagnosed at advanced stages of disease. This study evaluated the diagnostic value of ThinPrep (TP) bronchial brushing cytology in lung cancer. A total of 595 patients with suspicious lung cancer were enrolled in this study. The bronchial brushing samples were prepared by TP. The data were then compared to histology of lung tissue samples. Histologically, 479 of these 595 patients were diagnosed with lung cancer, including 223 cases of lung squamous cell carcinoma (SCC), 77 cases of lung adenocarcinoma (ADC), and 152 cases of small cell lung carcinoma (SCLC). The TP cytology revealed a total of 460 cases of lung cancer (including 232 SCCs, 91 ADCs, and 108 SCLCs). The TP cytological technique had 87.06% sensitivity and 62.93% specificity in the diagnosis of lung cancer. Specifically, TP cytology confirmed 195 of 223 SCCs, 47 of 77 ADCs, and 94 of 152 SCLCs. The TP cytology showed 87.44% sensitivity and 90.05% specificity for the diagnosis of SCC, with a Matthew''s correlation coefficient (MCC) of 0.820; while the sensitivity was reduced to 61.04% and the specificity was 90.93% for the diagnosis of ADC, with a MCC of 0.464. For the diagnosis of SCLC, the sensitivity was 61.84% and the specificity was 96.84%, with a MCC of 0.648. Thus, this study demonstrated the usefulness of TP bronchial brushing cytology in the early diagnosis of lung cancer, especially the early stage of lung SCC. A prospective clinical trial will verify these data before being translated into the clinic.     

P‐4TRANSFORMATION ZONE COMPONENT IN LIQUID BASED CERVICAL CYTOLOGY

Introduction: Quality assurance guidelines for the UK cervical screening programme recommend that more than 80% of cervical samples from women aged 20–50 years should contain adequate numbers of Transformation zone (TZ) cells i.e. 10 or more endocervical or squamous metaplastic cells. This study was conducted to assess the frequency of TZ component in Liquid Based Cytology (LBC) both for ThinPrep (TP) and SurePath (SP) LBC. Also to assess the degree to which this is recorded by individual screeners and to determine the percentage of samples with evidence of TZ component for the different smear takers. Method: All LBC cervical specimens received at a tertiary cytology centre in the year 2004 from women aged 20–50 years were included in the study. Evidence of TZ sampling was recorded as: TP = TZ present (10 or more TZ cells)TA = TZ absentTS = TZ scanty (less than 10 TZ cells)TN = atrophic smears, TZ cells not recognisable Results: The total number of LBC cervical cases was 7445. TP = 4300 (mostly primary care) and SP = 3145 (mostly colposcopy). Overall TZ sampling rate in LBC was 82%. TP = 77.17%; SP = 88.24%. When scanty TZ was included, the standard was met for both systems (TP = 93.7%; SP = 88.24%). Presence/absence of TZ component was recorded in 6370 cases (85.1%); range 0%–97.79%. 56.7% of smear takers achieved the minimum standard for TZ sampling. Discussion: The percentage of ThinPrep samples containing adequate TZ cells was 77.17% compared to SurePath, which was 88.24%. This may be due to different patient populations i.e. primary care versus colposcopy. Screeners recorded TZ sampling in approximately 85% of samples. 56.7% of smear takers met the standard for TZ sampling.     

Evaluation of thin-layer methods in urine cytology

Conventional cytospin smears prepared from urinary tract specimens were compared with two new thin layer techniques, i.e. ThinPrep and AutoCyte PREP. Cellularity, cell preservation, background features, detection rate, screening time and ease of preparation were evaluated. Thin-layer techniques when applied to urine cytology were found to improve cell yield and cell preservation, and reduce background artefact. The reporting rate for abnormal urothelial cells was comparable to conventional cytospin smears, as was screening time. Laboratory staff found the methodologies to be practicable and easily incorporated into a large routine diagnostic service. We conclude that a one-slide thin-layer urine preparation is comparable to four cytospin slides in the detection of urothelial abnormalities, and that both ThinPrep and AutoCyte PREP have comparable features.     

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.     

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.     

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.     

Proteomic analysis of high-grade dysplastic cervical cells obtained from ThinPrep slides using laser capture microdissection and mass spectrometry

The purpose of this discovery phase study was to identify candidate protein biomarkers for high-grade dysplastic cervical cells using mass spectrometry. Laser Capture Microdissection (LCM) was utilized to isolate high-grade dysplastic and normal cells from ThinPrep slides prepared from cervical cytological specimens. Following cell capture, samples were solubilized and proteins separated by gel electrophoresis in preparation for enzymatic digestion and liquid chromatography mass spectrometry analysis (LC-MS). Processed samples were subsequently analyzed using a linear ion trap coupled with a Fourier transform mass spectrometer (LTQ-FT MS). It was determined that both PreservCyt Solution and ThinPrep Pap Stain (Cytyc Corporation) were compatible with the sample processing and LC-MS analysis. In total, from 9 normal and 9 abnormal cervical cytological specimens, more than 1000 unique proteins were identified with high confidence, based on approximately 12,000 captured cells per specimen. Quantitative protein differences between HSIL (High-Grade Squamous Intraepithelial Lesion) and NILM (Negative for Intraepithelial Lesions or Malignancy) samples were determined by comparing the intensities of the representative (label-free) peptide ions. More than 200 proteins were found to exhibit a 3-fold difference in protein level. Interestingly, significant up-regulation of nuclear and mitochondrial proteins in HSIL specimens was noted. In several cases, the increased protein abundance observed in high-grade cells, as determined by quantitative LC-MS, was validated by immunocytochemical methods using ThinPrep cervical specimens. With the study of additional clinical specimens, the differential abundance of proteins in high-grade dysplastic cells versus morphologically normal cervical cells may lead to validated novel biomarkers for cervical disease.     

P‐21POSITIVE PREDICTIVE VALUE OF CERVICAL SMEARS REPORTED AS MILD DYSKARYOSIS

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.     

Evaluation of liquid-based cytology in cervical screening of high-risk populations: a split study of colposcopy and genito-urinary medicine populations

A split study evaluated the ThinPrep(R) PapTesttrade mark (TP; Cytyc Corp., Boxborough, MA) compared with current methodologies of cervical cytology in two high-risk cohorts. One thousand, three hundred cases from a colposcopy clinic and a genito-urinary medicine outpatient clinic were examined. The TP reported increased detection of all grades of dyskaryosis (mild, moderate and severe; + 4.5%) and a decrease in borderline and unsuitable cases (- 4.9%). Four cases of high-grade dyskaryosis (moderate or severe) were detected only using the TP, while an additional four cases classified as high-grade dyskaryosis with the TP were reported as borderline by our conventional methods. The split-study finding of increased sensitivity with the TP provides for improved clinical management of patients in our high-risk cohorts.