Liquid-based cytology in breast fine needle aspiration. Comparison with the conventional smear

OBJECTIVE: To compare the various cytologic features on AutoCyte Prep (ACP) (AutoCyte, Inc., Burlington, North Carolina, U.S.A.) and conventional preparation (CP) specimens from breast fine needle aspiration cytology material with a semi-quantitative scoring system. STUDY DESIGN: A total of 100 randomized cases were studied. In each case, 2 passes were performed. One pass was used for CPs (Giemsa and Papanicolaou stain). The other pass produced material for the ACP technique and Papanicolaou stain. Both the conventional and liquid-based preparations were studied independently by two observers and compared for cellularity, obscuring and/or informing background, representative diagnostic material, preservation of cytomorphologic features, presence of monolayer cells and architectural arrangement. RESULTS: Comparing the two preparations, the results were as follows: (1) ACP was superior to CP in 2 features, lack of obscuring background and presence of monolayer arrangement with preservation of cell architecture; (2) ACP was inferior to CP in 1 feature, lack of informing background; and (3) ACP was equal, with small deviations, to CP in the rest of the features evaluated: cellularity, representative diagnostic material, preservation of cell morphology and architectural arrangement. CONCLUSION: The new technology of liquid-based cytology in breast FNA showed a good correlation with CP plus the advantages of: (1) easier and less time consuming evaluation of cell morphology (clear background, no overlapping, smaller area to screen); (2) reproducibility, a factor of great importance to quality control; and (3) possibility of adjunctive investigations (immunocytology, flow cytometry) on the same material.     

A comparative study: conventional preparation and ThinPrep® 2000 in respiratory cytology

In order to compare and contrast conventional preparation (CP) with ThinPrep 2000 (TP) in respiratory cytology, 207 samples were divided equally and processed by the two different preparation methods, generating three CP and one TP slide per sample. No lesion identified by CP was missed by TP and there were no significant differences between TP and CP in the diagnostic categories. However, two cases of squamous cell carcinoma were detected on TP which had been classified as unsatisfactory and moderate squamous dyskaryosis, respectively, on CP. ThinPrep was found to be superior to CP in many respects as it provided standardized preparations in a greater proportion of cases and problems such as cell overlapping and background debris were markedly reduced. In several instances the diagnostic accuracy in CP was compromised by smears that were either too thick, too thin, or too scanty. Cell preservation was also better on TP when compared with CP, facilitating more accurate diagnosis and significantly reducing the primary screening and reporting time, especially of sputum samples. A major advantage of TP methodology is the fact that it facilitates optimal use of skilled cytotechnologists and streamlines the workflow in the laboratory.     

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.     

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.     

Liquid-based vs. conventional smears in fine needle aspiration of bone and soft tissue tumors

OBJECTIVE: To compare the accuracy of fine needle aspiration cytology of bone and soft tissue tumors utilizing ThinPrep (TP) (Cytyc Corporation, Boxborough, Massachusetts, U.S.A.) vs. conventional smears (CS). STUDY DESIGN: Fine needle aspiration cytology from bone and soft tissue tumors was processed and assessed for cellularity, nuclear and cytoplasmic preservation, cellular architecture and stromal background with both the TP liquid-based smear technique and conventional methods. RESULTS: An accurate diagnosis was made in 13% of TP cases as compared to 64% in CS cases. CONCLUSION: CS of fine needle aspiration sample is far superior to TP in diagnosing tumors of bone and soft tissues. Preservation of cytoplasmic features and cellular architecture was superior in conventionally prepared smears.     

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.     

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.     

Glandular lesions of the cervix on thin-layer Pap tests. Validity of cytologic criteria used in identifying significant lesions

OBJECTIVE: To determine the cytologic features that are most helpful in characterizing significant glandular lesions of the cervix observed on the ThinPrep (TP) Pap test (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) and to compare these features with those published for conventional smears. STUDY DESIGN: Thirty-nine TP preparations with cytologic evidence of glandular lesions of the cervix and histologic and/or clinical correlation were studied. These lesions included (1) 11 cases of benign/reactive conditions; (2) 10 cases of adenocarcinoma in situ (AIS), of which 1 had both AIS and carcinoma in situ; (3) 1 case of invasive adenocarcinoma; (4) 15 cases of squamous intraepithelial lesions and squamous cell carcinoma, including 4 with glandular involvement, and (5) 2 cases of adenosquamous cell carcinoma. These cases were reviewed by the first author without knowledge of the histologic diagnosis. Twenty-five previously published cytologic criteria were used to evaluate glandular cells on TP slides. Statistical analysis was performed using Fisher's exact test to determine the significance of the features studied. RESULTS: All glandular lesions had cytologic features on TP similar to those previously described on conventional smears. However, TP slides demonstrated enhanced nuclear features but less-preserved architectural patterns. Reactive lesions showed minimal overlapping without hyperchromasia or mitotic figures and with normal nuclear/cytoplasmic ratios. AIS and invasive adenocarcinoma cases had similar features. Increased cellularity and overcrowding were prominent, whereas feathering, rosettes and cell strips were present but subtle. CONCLUSION: Glandular lesions of the cervix on TP slides shared many of the characteristic features reported for conventional smears. However, nuclear details were more pronounced in TP slides, while architectural patterns, although present, were relatively subtle.     

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.     

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.     

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.     

Image analysis of peripheral compression artefacts of ThinPrep® liquid‐based cytology preparations

J. Choi, H. S. Shim, J.‐W. Song, S. W. Chae, Y.‐N. Lee, J. E. Kim and S. H. Kim
Image analysis of peripheral compression artefacts of ThinPrep^® liquid‐based cytology preparations Objective: ThinPrep (TP), one of the Food and Drug Administration‐approved liquid‐based cytology (LBC) preparations, is widely used for gynaecological and non‐gynaecological cytology samples. A unique physical artefact caused by the compression at the periphery in TP slides has not been adequately evaluated to date. Methods: We processed four established tumour cell lines (MKN28, MKN45, KG‐1 and NB4) and mononuclear cells isolated from whole blood over Ficoll‐Plaque for TP preparations. For this part of the study, we included five normal cervical LBC preparations. We then auto‐counted and auto‐measured the area, mean grey value and Feret’s diameter in both the inner disc and peripheral rim of the preparations by image morphometry. In addition, we compared the distribution of atypical cell groups in the peripheral rim and inner disc of 132 lung aspirates, 80 thyroid aspirates, 212 cerebrospinal fluids (CSFs) and 50 gynaecological samples. Results: The areas and Feret’s diameters of the cytoplasm in the peripheral compressed rim area were statistically larger than those of cells in the inner disc. The mean grey values of cells (cytoplasm and nucleus) in the peripheral compression rim were also smaller than those in the inner disc cells, leading to decreases in nuclear and cytoplasmic chromatism. Except for the mean grey values, the differences were not significant in the cervical samples. Conclusions: Cellular morphology may be markedly distorted in the peripheral rim, regardless of cell malignancy, which may lead to the misinterpretation of cells during the screening. Accordingly, cytological diagnosis based on the findings within the peripheral rim should take this phenomenon into account. Compressed cells found in the peripheral rim should be interpreted with caution when TP slides are used for cytopathological diagnosis.     

Criteria for the diagnosis of fibroepithelial lesions of the breast with liquid-based cytology

OBJECTIVE: To establish diagnostic criteria for diagnosing and differentiating fibroepithelial lesions of the breast on ThinPrep (Cytyc Corp., Boxborough, Massachusetts, U.S.A.). STUDY DESIGN: Eighty-four fibroepithelial lesions were sampled by ultrasound-guided aspiration biopsy. Based on smears and histologic correlates, there were 55 fibroadenomas, 26 papillary neoplasms and 3 phyllodes tumors. The ThinPrep slides for each sample were reviewed retrospectively and evaluated for specific morphologic and cytologic features. RESULTS: On ThinPrep slides, 95% of the fibroadenomas had a predominance of single myoepithelial nuclei, 89% had staghorn clusters, and 47% had myxoid stroma. Among the papillary neoplasms, 8% had a predominance of single columnar ductal cells, 31% had papillary groups, 23% had vessels, and 27% had collagenous spherulosis. The ThinPrep preparations of the phyllodes tumors showed that 67% had single myoepithelial nuclei, 33% had a predominance of single ductal cells, 67% had staghorn clusters, and 0% had myxoid stroma. A majority of the fibroadenomas and the papillary neoplasms showed mild to moderate ductal epithelial hyperplasia. A majority of the phyllodes tumors showed moderate ductal epithelial hyperplasia. CONCLUSION: Fibroepithelial lesions of the breast can be accurately differentiated using ThinPrep samples based on the evaluation of specific cytologic and morphologic features, including the presence of staghorn clusters, fibromyxoid stroma, vessels, collagenous spherulosis, papillary clusters and predominance of myoepithelial nuclei or columnar cells in the background. However, the degree of ductal epithelial hyperplasia does not aid in the diagnosis.     

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.     

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.     

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.     

Analysis of urine cytology tests in 120 paired cases

OBJECTIVE: To evaluate the smear quality and diagnostic accuracy of ThinPrep processing in comparison to conventional Cytospin technique for urinary cytology. STUDY DESIGN: ThinPrep and Cytospin techniques were retrospectively evaluated by 2 observers in a double-blinded, randomized fashion. Each quality parameter was scored using a semi-quantitative score of 1-3. Diagnostic accuracy indices were calculated with biopsy histology as the gold standard. RESULTS: Quality of cellular distribution and cell preservation were better with Cytospin preparations, whereas ThinPrep smears were superior in terms of stain distribution and cleaner slide background. However, the only significant differences observed were in cellular distribution and a clean background (p < 0.05). Sensitivity and positive and negative predictive values were higher with Cytospin than the ThinPrep technique (90.0%, 94.7% and 71.4% vs. 80.0%, 94.1% and 55.6%, respectively). Conversely, the specificity of both techniques was comparable. CONCLUSION: The Cytospin smears were of better quality than those prepared by the ThinPrep technique. Although both techniques resulted in similar diagnostic accuracies in negative cases, the ThinPrep preparations were not found to be superior to Cytospin smears in diagnosing positive urinary cytology.     

Validation of a multicolor interphase fluorescence in situ hybridization assay for detection of transitional cell carcinoma on fresh and archival thin-layer, liquid-based cytology slides.

OBJECTIVE: To evaluate the feasibility of performing multicolor interphase fluorescence in situ hybridization (FISH) on ThinPrep slides of transitional cell carcinoma (TCC). STUDY DESIGN: Slides from 20 voided urine specimens were prepared by the ThinPrep technique (Cytyc, Boxborough, Massachusetts, U.S.A.), pretreated using a pretreatment kit and subjected to hybridization with the multicolor FISH probe UroVysion (Vysis, Downers Grove, Illinois, U.S.A.). Archival slides were placed in xylene, destained in alcohol and washed prior to pretreatment. Urines from patients with cytology-positive, biopsy-proven grade 1 (n = 5), 2 (n = 7) and 3 (n = 5) TCC and negative cytology and biopsy (n = 3) were selected. Freshly prepared (n = 10) and archival (n = 10) slides were used. RESULTS: All carcinoma cases were FISH positive (> 5 cells with complex abnormalities of > or = 2 studied chromosomes per slide). None of the normal samples were aneusomic. Gain of chromosomes 3, 7 and 17 constituted the majority of positive cases. Proper destaining and slight decrease in stringency wash conditions enabled reliable detection of signals in archival cases. CONCLUSION: Routine ThinPrep slides can be used for multicolor interphase FISH analysis of urine cytology specimens. Archival slides provide the opportunity to analyze by FISH the nature of atypical cells identified by cytology. This revised method allows FISH technology more accessibility for routine use in cytology laboratories.     

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.     

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.