Evaluation of PAPNET--a semiautomated system used in the screening against cervical cancer

The PAPNET-system is a current example of automated technological progress in the pathological laboratory field. As the first Department of Pathology in Denmark, we have tested the applicability of this semi-automatical screening system in screening against cervical cancer. 3000 prospectively selected cervical smears were entered into the project. 1500 of these were first prescreened by the use of PAPNET and the negative slides were then manually rescreened. The remaining 1500 slides consisted of manually screened smears diagnosed as negative or inadequate. They were subsequently rescreened by the use of PAPNET. We only found one false negative smear in each group. Compared with histological follow-up the diagnoses CIN 1-3 were histologically confirmed in both groups. The PAPNET-assisted screening of cervical smears is faster, more valid and less fatiguing than the conventional screening method. Nevertheless, our results show no diagnostic quality improvement by the use of PAPNET. This is probably due to a strict screening procedure and a limited work load of a maximum of about 40-50 slides per cytotechnologist a day in our laboratory.     

Evaluation of the PAPNET system for prescreening triage of cervicovaginal smears

OBJECTIVE: To assess the PAPNET System for prescreening triage of cervical smears. STUDY DESIGN: We prospectively prescreened 5,170 consecutive cervicovaginal smears with the PAPNET System. The slides were then manually screened by cytotechnologists blinded to the PAPNET diagnoses. Cases identified as abnormal by either PAPNET or manual screening were reviewed by a cytopathologist. The PAPNET and manual diagnoses were correlated. RESULTS: Diagnostic concordance between PAPNET and manual screening was seen in 4,340 (84%) of the cases (3,167 negative, 1,038 abnormal and 135 unsatisfactory). Noncorrelation between PAPNET and manual diagnosis occurred in 794 cases (543 abnormal by PAPNET and negative manually, 228 negative by PAPNET and abnormal manually, 8 abnormal by PAPNET and unsatisfactory manually, 29 unsatisfactory by PAPNET and negative manually, 7 negative by PAPNET and unsatisfactory manually). The diagnostic sensitivity of the PAPNET System was 82%, diagnostic specificity 85%, predictive value of a positive test 66% and predictive value of a negative test 93.4%. The false negative fraction of PAPNET was 6.4% for low grade squamous intraepithelial lesion and above. CONCLUSION: PAPNET performed effectively for prescreening triage, increasing the accuracy of screening and reducing the screening time.     

Dietary thiamin supply during gestation effects thiamin status of lactating rats and their suckling offspring

A paired-comparison study of manual and automated (PAPNET) screenings of cervico-vaginal smears (Pap tests) was conducted to determine whether primary PAPNET screening was a reliable alternative to manual screening. A series of 5,037 consecutive Pap tests was first screened by the manual method. Next they were scanned by the PAPNET system, the DAT tapes were reviewed, and using a nonspecific triage protocol, abnormal tests were identified for limited, manual rescreening. False-negative rates (FNR) for each method were calculated and analyzed for due cause. By manual and PAPNET screening, respectively, there were 436 (8.6%) and 250 (4.9%) abnormal results. Manual screening missed 18 abnormals (5 SIL) and PAPNET 202 (7 SIL). The primary, manual screenings relating to the PAPNET false-negative tests were reviewed and revised to normal in 30. Based on the changes in the other 172 tests, cellular features ostensibly missed by the PAPNET system were listed to form part of a specific triage protocol, and were used to scrutinize the companion 172 DAT tapes: 150 tapes were abnormal. The manual FNR for an abnormal (SIL) result was 4% and (8.8%), respectively. Equivalent FNR pre- and postreviews for the PAPNET system were 44.6% (10.6%) and 5.2% (1.3%), respectively. This study discovered that the evaluation of some cell features in monitor-based, video images was the most important factor limiting the application of the PAPNET system as a primary screener. When governed by a specific triage protocol incorporating these features, primary PAPNET screening has the potential to equal the laboratory threshold of manual screening and be a better detector of SIL.     

Significant reduction in the rate of false-negative cervical smears with neural network-based technology (PAPNET Testing System)

False-negative cervical Pap smears may lead to disability or death from carcinoma of the uterine cervix. New computer technology has led to the development of an interactive, neural network-based vision instrument to increase the accuracy of cervical smear screening. The instrument belongs to a new class of medical devices designed to provide computer-aided diagnosis (CADx). To test the instrument's performance, 487 archival negative smears (index smears) from 228 women with biopsy-documented high-grade precancerous lesions or invasive cervical carcinoma (index women) were retrieved from the files of 10 participating laboratories that were using federally mandated quality assurance procedures. Samples of sequential negative smears (total 9,666) were retrieved as controls. The instrument was used to identify evidence of missed cytological abnormalities, including atypical squamous or glandular cells of undetermined significance (ASCUS, AGUS), low-grade or high-grade squamous intraepithelial lesions (LSIL, HSIL) and carcinoma. Using the instrument, 98 false-negative index smears were identified in 72 of the 228 index women (31.6%, 95% confidence interval [CI]: 25% to 38%). Disregarding the debatable categories of ASCUS or AGUS, there were 44 women whose false-negative smears disclosed squamous intraepithelial lesions (SIL) or carcinoma (19.3%; 95% CI: 14.2% to 24.4%). Unexpectedly, SILs were also identified in 127 of 9,666 control negative smears (1.3%; 95% CI: 1.1% to 1.5%). Compared with historical performance data from several participating laboratories, the instrument increased the detection rate of SILs in control smears by 25% and increased the yield of quality control rescreening 5.1 times (P < 0.0001). These data provide evidence that conventional screening and quality control rescreening of cervical smears fail to identify a substantial number of abnormalities. A significant improvement in performance of screening of cervical smears could be achieved with the use of the instrument described in this report.     

Social support among African-American adults with diabetes. Part 1: Theoretical framework

BACKGROUND: Atypical squamous cells of undetermined significance (ASCUS) is a cytopathologic term used to describe cases without specific pathologic substratum. Between 10-60% of ASCUS cases correspond to squamous intraepithelial lesions (SIL). METHODS: The objectives of this study were: 1) to detect the pathologic significance of ASCUS in study patients, 2) to determine whether PAPNET identifies these cases, and 3) to compare the results of PAPNET with those of a second conventional screening. One hundred and sixty-three consecutive patients with the cytologic diagnosis of ASCUS and adequate follow-up were selected. Of these, 111 patients had colposcopic lesions and biopsies were performed; in the remaining 52 cases colposcopy was negative, as were 3 consecutive annual Papanicolaou smears. In a blind review, all 163 cases were rescreened using PAPNET. A second manual screening was performed for comparison. RESULTS: One hundred and twenty-six of the 163 cases (77.3%) showed no SIL on biopsy or follow-up. Of the 37 pathologic cases, the diagnosis was koilocytosis (flat condyloma) in 13 cases (8%), cervical intraepithelial neoplasia (CIN) type I in 11 cases (6.8%) low grade SIL [LSIL] in a total of 24 cases [14.8%]), and CIN II-III or high grade SIL (HSIL) in 11 cases (6.8%). In the review using PAPNET, 57 previous ASCUS cases were classified correctly as negative, and 7 of 13 koilocytosis cases (54%), 9 of 11 CIN I cases (82%), and 7 of 11 CIN II-III cases (64%) were diagnosed correctly. In the second conventional screening, 74 cases were negative and 77 cases were ASCUS; only 3 of 13 koilocytosis cases (23%), 4 of 11 CIN I cases (36.4%) and 5 of 11 CIN II-III cases (45.5%) were reclassified correctly. CONCLUSIONS: Among 163 patients with ASCUS, 77.3% had no precancerous squamous lesions. Concordance with definitive diagnosis was more accurate in our study using PAPNET analysis (Kappa index [K] = 0.7158) than by second conventional screening (K = 0.4537). Furthermore, we reclassified 35% of smears as negative and 15% as SIL.     

Cell cycle arrest and release in starfish oocytes and eggs

A neural net-based, semiautomated, interactive computerized cell analysis system (The PAPNET system, Neuromedical Systems, Suffern, NY) was used to examine cells from 138 esophageal smears obtained by lavage, brushings, or balloon from as many patients. From each smear, trained human observers examined 128 cell images selected by the machine. Abnormal cells were identified in all 35 patients with cancer, whether esophageal, gastric, oral, or metastatic. Further, in 11 smears, the displayed images allowed the recognition of effects of radiotherapy and, in 14 smears, the diagnosis of a specific tumor type, such as squamous cell carcinoma (8 patients) or adenocarcinoma (6 patients). In 3 additional cases, the diagnosis of "carcinoma, not further specified," was established. One case of esophageal carcinoma in situ, not previously recognized on a smear or in the biopsy specimen, and one case of gastric adenocarcinoma, not recognized in the smear, were identified in PAPNET-generated images. The possible application of the apparatus to the triage of smears and population screening for esophageal and gastric carcinoma precursors is discussed.     

Bone tumor radiograph review by pathologists prior to pathologic diagnosis: a receiver operator curve analysis of diagnostic utility

OBJECTIVE: To assess the performance of quick rescreening as an internal quality control for cervical smears previously screened as negative and to compare this method with clinically indicated rescreening of negative smears and with further 10% random rescreening. STUDY DESIGN: In a small-workload laboratory with many different types of indications for cytology, during a three-month period, all gynecologic cytology smears considered negative for significant findings (anything above atypical squamous cells of undetermined significance (ASCUS)/atypical glandular cells of undetermined significance (AGUS) in the Bethesda System) or inadequate were quickly rescreened using a 10 x objective. RESULTS: Of the total 2,188 smears processed, 164 (7.5%) were excluded from rapid review because they were positive on routine screening, and 2,024 cases were subjected to rapid rescreening: 1,925 (95.1%) cases were considered negative and 99 (4.9%) positive for significant findings; 58 of the latter were confirmed and 41 not confirmed by the cytopathologist's detailed examination. The 58 confirmed cases were classified as: 43 ASCUS/AGUS, 14 of low grade squamous intraepithelial lesion and 1 of invasive cancer. No cases of high grade squamous intraepithelial lesion were detected. CONCLUSION: Considering that the routine screening and internal quality control of the laboratory had detected 117 positive cases, the additional 58 represent a definite increase in the efficiency of a small-workload laboratory. In such a clinical setting, no additional case of a high grade lesion was detected by rapid rescreening. The increase in cost and time was considered very reasonable, and the method was incorporated as quality control for the laboratory. Clinically indicated rescreening of negative smears and random 10% rescreening after random rescreening did not add significantly to quality assurance.     

Percentages of cervical cytologic diagnoses as a quality assurance method

OBJECTIVE: To demonstrate empirically that the efficiency of rescreening to discover false negative cytologic diagnoses is greatly enhanced by prospectively stratifying accessions according to risk level. STUDY DESIGN: We stratified accessions from 11 clinical sources and established the rate of diagnoses according to three categories: (1) "within normal limits"/"benign cellular changes" (WNL/BCC), (2) "atypical squamous/glandular cells of undetermined significance" (ASCUS/AGCUS) and (3) "squamous intraepithelial lesion/invasive carcinoma" (SIL/CA). We then prospectively rescreened all negative smears from sources with rates of positive diagnoses (ASCUS/AGCUS and SIL/CA) in excess of 20% and 5% of negative smears from sources with rates of positive diagnoses < 20%. We compared the detection rates of false negatives on rescreening target groups with random rescreening of 10% of all negative smears. RESULTS: The rates of SIL/CA, ASCUS/AGCUS and WNL/BCC varied from 0 to 43%, 4% to 14% and 46% to 94%, respectively. Rescreening 10% of all negative smears revealed a false negative fraction of 3%; rescreening target groups revealed a false negative fraction of 5.9%. CONCLUSION: The yield of prospectively detected false negative diagnoses was significantly increased by targeting high-risk accession groups. When cytology laboratories serve diverse populations, stratifying accessions by risk to permit increased sampling from the proportionately higher risk categories is a simple and effective device to maximize the yield and benefit from rescreening.     

Does the menstrual cycle and use of oral contraceptives influence the risk of low back pain? A prospective study among female soccer players

BACKGROUND: There is an increasing number of articles regarding the long term follow-up of Papanicolaou (Pap) smears with the diagnosis of atypical squamous cells of undetermined significance (ASCUS). Much controversy exists regarding the management of patients with this diagnosis. In a prior study in 1992, the authors performed automated rescreening of 101 ASCUS cases and 91 negative (control) cases. They found that through PAPNET-directed rescreening, 35 of 101 ASCUS cases (35%) could be reclassified as a squamous intraepithelial lesion (SIL). METHODS: These 192 women were followed since 1992 through manual look backs of subsequent Pap smears and surgical biopsies over a 4-year period. The population studied was comprised of predominantly black women between the ages of 14 and 85 years. The majority were considered a high risk population because many had a history of several sexual partners and multiple pregnancies. RESULTS: Eighteen of 74 patients (24.3%) with an original diagnosis of ASCUS were found on subsequent Pap smears to have an SIL. Only 4 of 64 patients (6%) who originally had a negative Pap smear subsequently were found to have a low grade squamous intraepithelial lesion (LGSIL) within 4 years. Through ordinal logistic regression analysis, it was found that patients with an ASCUS diagnosis had a risk of developing SIL that was 2.6 times greater than the risk for patients with a negative smear diagnosis. Comparing the surgical biopsies in the control and ASCUS groups, there was no statistically significant difference in the risk of developing SIL. This may be because the number of follow-up biopsies were small. CONCLUSIONS: A statistically significant difference of the risk of developing SIL exists between patients with a negative smear versus those with an ASCUS smear. Long term follow-up is essential in the management of the patients with an ASCUS smear because there is clearly an increased risk of developing SIL.     

Analysis of false-negative and underreported smears in the Florence district screening program for cervical carcinoma

AIMS AND BACKGROUND: To review false-negative or underreported (reactive changes, squamous or glandular atypia) smears performed in women developing histologically proven CIN2 or more severe lesions within 24 months and evaluate error causes. The study setting was the Florence District cervical cancer population-based screening: about 60,000 women age 25-60 years screened per year. METHODS: 118 false-negative or underreported cases were identified at screening files-cancer Registry matching, and the original smears were reviewed by six independent readers to judge smear adequacy and error type. RESULTS: Sampling errors (reported as inadequate, negative or less severe than CIN1 at review) accounted for 74% and screening/interpretation errors (reported as CIN1 or more severe at review) accounted for 26% of studied cases. Screening/interpretation errors were more likely ascribed to misinterpretation and underreporting than to misperception of cellular abnormalities. CONCLUSIONS: Quality control should above all address the problem of sampling adequacy. Due to the rarity of misperceived abnormalities (true screening errors), manual or automated rescreening of negative smears would not be an effective procedure for quality control.     

The AutoPap system for primary screening in cervical cytology. Comparing the results of a prospective, intended-use study with routine manual practice

OBJECTIVE: To evaluate the effectiveness of the AutoPap System in detecting abnormal and normal cervical smears when used in a primary screening/quality control mode, as compared with currently established laboratory practices. STUDY DESIGN: Slides were obtained prospectively and were initially processed in the routine fashion with cytotechnologist screening followed by 10% random quality control rescreening. Slides were then processed on the AutoPap System and allocated into the following groups: (1) approximately 25% of the lowest-ranking slides were placed in the laboratory's archives as within normal limits; (2) the remaining approximately 75% of slides were subjected to manual screening. Approximately 15% of the highest-ranking slides in this group underwent quality control rescreening. For each slide needing manual screening, the cytotechnologist was supplied with a report giving the ranking score of that slide. All discrepant slides for either adequacy or diagnosis were subjected to a truth-determination process. The results obtained from the two arms of the protocol were then compared. RESULTS: The AutoPap System-assisted arm of the study was superior to the current practice arm for the identification of abnormal slides at the level of atypical squamous cells of undetermined significance and above (ASCUS+), low grade squamous intraepithelial lesion (LSIL) and higher LSIL+. AutoPap System-assisted practice was equivalent to current practice for the identification of unsatisfactory and satisfactory but limited by slides. All results showed statistical significance. In addition, AutoPap System-assisted practice in the study indicated improved specificity of diagnosis. CONCLUSION: AutoPap System-assisted practice shows superior sensitivity and specificity when compared to current practice. Its clinical use as a primary screening device should improve the overall practice of cervical cytology as well as provide potential enhancement in overall laboratory productivity.     

The in situ polymerase chain reaction for detection of chlamydia trachomatis

The in situ polymerase chain reaction (PCR) is a technique that has important applications in the diagnosis of viral and bacterial diseases. This study investigated an in situ PCR assay established to detect the presence of Chlamydia trachomatis in endocervical swabs. In addition, histological sections of endocervical squamous cell carcinoma were analyzed because previous studies had revealed a significant association with C. trachomatis. A total of 20 cervical neoplasms (squamous cell carcinoma in situ; n = 10; invasive squamous cell carcinoma; n = 10) and endocervical smears taken from five patients with and without inflammatory changes were analyzed by conventional PCR. Chlamydial DNA was found in 10 histological samples (six carcinomas in situ, four invasive carcinomas) and in one endocervical swab from a patient with known C. trachomatis infection. Positive specimens were used for establishing an in situ PCR assay (IS-PCR). After IS-PCR, these samples showed dense cytoplasmic staining of endocervical cells (smears) and non-neoplastic epithelial cells (cervical neoplasms). The other tumor samples and smears did not demonstrate positive PCR reaction. The results indicate that in situ PCR is an effective technique for localizing C. trachomatis in target cells because IS-PCR detection of chlamydial DNA correlated with histological and cytological features.     

Efficacy of ThinPrep preparation of cervical smears: a 1,000-case, investigator-sponsored study

The diagnoses of 1,000 pairs of conventional Papanicolaou (Pap) smears and ThinPrep preparations were compared. Cervical cells were collected using an Ayre spatula and endocervical brush. The conventional smear was made first, the collection devices were rinsed into PreservCyt solution, and the slides were prepared using the ThinPrep Processor. The diagnoses of the paired smears agreed in 988 of the 1,000 cases (98.8%), including 949 negatives, 28 atypicals, 9 low grade squamous intraepithelial lesions (LGSIL), and 2 high grade squamous intraepithelial lesions (HGSIL). Five cases where LGSIL or HGSIL was found on the ThinPrep slide were negative or atypical on the conventional smear. No conventional smear abnormalities were missed on the ThinPrep slide. Although not statistically significant, this difference indicates that the ThinPrep method gives a better diagnosis of abnormalities than the conventional method. The ThinPrep method was acceptable to participating physicians and ThinPreps were easier and faster to screen than conventional smears.     

Rescreening in gynecologic cytology. Rescreening of 8096 previous cases for current low-grade and indeterminate-grade squamous intraepithelial lesion diagnoses--a College of American Pathologists Q-Probes study of 323 laboratories

OBJECTIVE: To quantitate, characterize, and analyze errors identified in the rescreening of previous gynecologic cytology specimens with original diagnoses of within normal limits or benign cellular changes for current cases diagnosed as low-grade squamous intraepithelial lesion or squamous intraepithelial lesion of indeterminate grade. DESIGN AND SETTING: College of American Pathologists Q-Probes laboratory quality improvement study in 323 laboratories. MAIN OUTCOME MEASURE: False-negative rate in cases rescreened as a result of a current cytologic diagnosis of low-grade squamous intraepithelial lesion or squamous intraepithelial lesion of indeterminate grade. RESULTS: A total of 8096 smears performed within the 5 years preceding the current examination were rescreened. Of the rescreened cases, 284 (3.5%) were reclassified as a squamous intraepithelial lesion or carcinoma, 474 (5.9%) as atypical squamous cells of uncertain significance, 7 (0.09%) as atypical glandular cells of uncertain significance or glandular intraepithelial lesion, and 39 (0.5%) as unsatisfactory. Ninety-three percent (261/280) of all false-negative cases were identified in cases from the previous 3 years. CONCLUSION: Rescreening archival cytology cases previously diagnosed as within normal limits or benign cellular changes for current cases diagnosed as low-grade squamous intraepithelial lesion or squamous intraepithelial lesion of indeterminate grade will identify screening and diagnostic errors. This may be a useful quality improvement monitor in many laboratories.     

Use of the Thin Prep Pap Test in clinical practice

The Thin Prep Pap Test (Cytyc Corp., Boxborough, MA) received approval by the Food and Drug Administration in May 1996 as an alternative to the traditional conventional smear. The present direct-to-vial study assessed the utility of thin-layer technology for cervicovaginal screening in clinical practice. From May 1997-February 1998 (10 mo), 15,006 cervical smears were processed and evaluated; of these, 5,423 (36.1%) were conventional smears (CS) and 9,583 (63.9%) were Thin Prep slides (TP). Both methods were analyzed to compare specimen adequacy and detection rates of cervical lesions. The TP method reduced the "satisfactory but limited by" rate by 97% and the unsatisfactory rate by 63%. For low-grade squamous intraepithelial lesions (LSILs), TP slides yielded 3.6% (348/9,583) as compared to 0.98% (53/5,423) for CS, an increase of 267%. The TP method detected a threefold increase in the number of high-grade squamous intraepithelial lesions (HSILs) of 1.0% (100/9,583), as compared to 0.3% (17/5,425) for the CS group. The atypical squamous cells of undetermined significance/squamous intraepithelial lesion (ASCUS SIL) ratio was reduced by 54% in the TP group. In routine usage in our laboratory, the Thin Prep Pap Test yielded a significant increase in the detection of LSILs and HSILs as compared to conventional smears. Specimen adequacy was significantly improved.     

Detecting structural changes at the molecular level with Fourier transform infrared spectroscopy. A potential tool for prescreening preinvasive lesions of the cervix

OBJECTIVE: To study cervical exfoliated cells with Fourier transform infrared spectroscopy (FTIR). STUDY DESIGN: Consecutive samples from 133 women attending the Dysplasia Clinic, Ottawa Civic Hospital, were collected in balanced electrolyte solution. After centrifugation, two smears were prepared for routine screening. The remainder of the pellet was frozen for FTIR spectroscopic study. RESULTS: In 120 samples, adequate material was available for spectroscopic study. All smears from 17 women with normal spectra were within normal limits (WNL). One hundred three spectra were abnormal. The corresponding smears were interpreted as: 41 low grade squamous intraepithelial lesions, 20 high grade squamous intraepithelial lesions, 6 atypical squamous cells of undetermined significance, 17 cases with benign cellular changes, and 19 WNL. Ten of 17 cases with benign cellular changes had characteristic spectra consistent with inflammatory changes. CONCLUSION: FTIR spectroscopy is a highly sensitive technique for detecting cervical abnormalities and a potential tool for prescreening preinvasive lesions of the cervix.     

Order of endocervical and ectocervical cytologic sampling and the quality of the Papanicolaou smear

OBJECTIVE: To determine whether the order of cell collection, endocervical or ectocervical cells first, has an effect on the quality of the Papanicolaou smear. METHODS: One thousand smears were obtained using an Ayre spatula and an endocervical brush. In 500 cases the endocervical brush was used first, and in 500 cases the spatula was used first. All Papanicolaou smears were collected by resident physicians in our university hospital gynecologic clinics. A smear was considered limited for interpretation for the following reasons: 1) lack of endocervical component, 2) obscured by blood, 3) obscured by inflammation, 4) drying artifact, and 5) too thick. RESULTS: The brush-first group had 405 (81%) adequate smears compared with 410 (82%) adequate smears in the spatula-first group. More smears were obscured by blood when the brush was used first (22 or 4.4% compared with three or 0.6%, P < .001). No endocervical component (ie, metaplastic cells, endocervical cells, or mucus) was found in 29 (5.8%) smears from the brush-first group compared with 45 (9.0%) of the spatula-first group, an insignificant difference. More squamous intraepithelial lesions were found when the spatula was used first (55 or 11% compared with 35 or 7.0%, P < .05). CONCLUSION: The quality of the Papanicolaou smear can be improved by using the Ayre spatula first followed by the endocervical brush. Fewer smears will be obscured by blood, which could result in more squamous intraepithelial lesions being detected.     

Evaluation of the ThinPrep Pap test as an adjunct to the conventional Pap smear

OBJECTIVE: To evaluate the ThinPrep Pap test as an adjunct to the conventional Pap smear. DESIGN AND SETTING: Prospectively collected cervical samples were split for independent screening at a large specialised private gynaecological pathology practice in Sydney. MAIN OUTCOME MEASURES: Detection of additional significant abnormalities (cervical intraepithelial neoplasia 1, or more severe); changed management recommendations from "repeat smear in 12 months" or "...six months" to "colposcopy", a reduction in unsatisfactory reports. RESULTS: 35,560 paired (split-sample) conventional and ThinPrep slides were prepared. Significant abnormalities were detected in 724 conventional smears (2%). Additional significant abnormalities were found in 85 ThinPrep slides whose corresponding conventional smear was negative or unsatisfactory even after review, representing a 12% increase in the detection of significant abnormalities. As a result of the addition of ThinPrep, management recommendations were changed from "repeat smear in 12 months" or "...six months" to "colposcopy" for 89 of 1669 women whose conventional Pap smears showed minor non-specific changes or papillomavirus. There were 1258 conventional smears (3.5%) that were unsatisfactory compared with 235 ThinPrep slides (0.7%); for only 74 samples (0.2%) were both slides unsatisfactory. CONCLUSIONS: The addition of the ThinPrep Pap test improves detection and clinical management of cervical abnormalities, and reduces the number of unsatisfactory samples which would otherwise require repeat tests.     

Immunological identification of a basic homologue to acidic virus-inducible cucumber peroxidase

BACKGROUND: The 1991 Bethesda System for cervical/vaginal cytology reporting defined adequacy criteria for the unsatisfactory designation. Most laboratories have implemented these criteria, but clinical implications have not been established. METHODS: Researchers at two university hospitals retrieved by computer search all unsatisfactory Papanicolaou (Pap) smears taken between January 1994 and July 1995. Of 71,872 total Pap smears, 208 (0.3%) were unsatisfactory (corresponding atypical rate of 9% and a dysplasia/carcinoma rate of 6.5%). Time interval to follow-up and clinicopathologic outcome were determined. RESULTS: Approximately 26% of unsatisfactory Pap smears were from patients with a history of epithelial abnormalities. The majority (129 of 208 specimens; 62%) of follow-up Pap smears or biopsies occurred within 6 months, 5.7% within 6-12 months, and 1.4% in 12-18 months. Approximately 31% had no follow-up. The first repeat Pap smear or histologic specimen in 144 patients with follow-up was negative in 107 (74%), unsatisfactory in 6 (4%), atypical squamous cells of undetermined significance in 15 (10%), squamous intraepithelial lesion (SIL) in 13 (9%), and malignant in 3 (2%). Nonmalignant conditions contributing to the unsatisfactory smears on histologic specimens (12%) included cervicitis, endometritis, endometrial hyperplasia, and polyps. Progressive abnormalities after the first repeat specimen were noted in 7 patients (5%). A total of 23 of 144 initial unsatisfactory specimens (16% )were found to be from patients diagnosed with SIL or malignancy when all follow-up specimens were analyzed. CONCLUSIONS: The majority of patients with unsatisfactory Pap smears had follow-up studies within 6 months. A significant number (16%) of those with follow-up had eventual diagnoses of SIL or neoplasia. Benign pathologic conditions also contributed to unsatisfactory smears. This patient subset was more likely to have a history of abnormalities, confirming the importance of peer/hierarchical review of unsatisfactory smears.     

Chemiluminescent in situ hybridization for the detection of cytomegalovirus DNA

A chemiluminescent in situ hybridization assay that could combine the sensitivity of chemiluminescent substrates, the specificity of digoxigenin-labeled probes, and the spatial morphological resolution and localization of the signal of the in situ hybridization was developed for the detection of cytomegalovirus (CMV) DNA. CMV DNA in cultured CMV-infected cells and in different clinical samples (tissue sections and cellular smears) was detected using digoxigenin-labeled probes constructed in our laboratory that were immunoenzymatically visualized employing anti-digoxigenin Fab fragments labeled with alkaline phosphatase and the chemiluminescent adamantil-1,2-dioxetane phenyl phosphate substrate for alkaline phosphatase. The luminescent signal from the hybrid formation was detected, analyzed, and measured with a high performance, low light level imaging luminograph apparatus connected to an optical microscope and to a personal computer for quantitative image analysis. Increasing values of emitted photons per second per infected cell, corresponding to the presence of hybridized CMV DNA, could be found in infected cells fixed at various times after infection, following the CMV replication cycle. When the assay was performed on different clinical samples from patients with acute CMV infections, CMV DNA was detected in all positive samples tested, both in cellular samples and in frozen and paraffin-embedded tissue sections, proving specific and sensitive. The chemiluminescent in situ hybridization assay developed in this work can be a useful tool for a sensitive and specific diagnosis of viral infection and can be easily adapted to detect and study any specific gene sequence inside the cells. The assay may also be promising for an estimation and quantification of nucleic acids present in tissue samples or cellular smears and for imaging gene expression in cells.