P-11THE IMPACT OF INTRODUCING LIQUID BASED CYTOLOGY INTO A ROUTINE SCREENING LABORATORY

Introduction:  A glacial acetic acid wash performed retrospectively or prospectively on visibly bloodstained cervical ThinPrep® specimens can reduce the unsatisfactory rate and increase the number of diagnostic epithelial cells. This study was undertaken to determine which specimens are most likely to benefit from a prospective glacial acetic acid wash.
Methods:  Bloodstained ThinPrep® specimens selected for routine lysing prior to processing were macroscopically assessed and scored based on the level of blood present (+ to +++). Both unlysed and lysed slides were prepared from each specimen and microscopically examined.
Results:  Fifty-eight specimens (32 scored +, 12 ++ and 14+++) were assessed. Three unlysed slides prepared from the ++ specimens and 12 from +++ specimens were evaluated as unsatisfactory due to excessive blood and inadequate numbers of squamous cells. In contrast, only one of the unlysed slides from the 32 + specimens was considered to be unsatisfactory. Almost all the lysed slides were satisfactory and generally more cellular than the unlysed slides. Abnormal cells were found in four cases (both unlysed and lysed paired slides).
Discussion:  Although the acetic acid wash increases cellularity of bloodstained ThinPrep® specimens, prospectively lysing all bloodstained specimens is an unnecessary procedure. Lysing only very heavily bloodstained specimens prior to processing will reduce laboratory workload, costs and the possibility of specimen mix up. Occasionally a retrospective wash may be required but screening staff should be aware that although blood may be present on an unlysed ThinPrep® slide, a lysed slide should not be requested unless there are insufficient numbers of squamous cells present.     

P‐11THE IMPACT OF INTRODUCING LIQUID BASED CYTOLOGY INTO A ROUTINE SCREENING LABORATORY

Introduction: A glacial acetic acid wash performed retrospectively or prospectively on visibly bloodstained cervical ThinPrep® specimens can reduce the unsatisfactory rate and increase the number of diagnostic epithelial cells. This study was undertaken to determine which specimens are most likely to benefit from a prospective glacial acetic acid wash. Methods: Bloodstained ThinPrep® specimens selected for routine lysing prior to processing were macroscopically assessed and scored based on the level of blood present (+ to +++). Both unlysed and lysed slides were prepared from each specimen and microscopically examined. Results: Fifty‐eight specimens (32 scored +, 12 ++ and 14+++) were assessed. Three unlysed slides prepared from the ++ specimens and 12 from +++ specimens were evaluated as unsatisfactory due to excessive blood and inadequate numbers of squamous cells. In contrast, only one of the unlysed slides from the 32 + specimens was considered to be unsatisfactory. Almost all the lysed slides were satisfactory and generally more cellular than the unlysed slides. Abnormal cells were found in four cases (both unlysed and lysed paired slides). Discussion: Although the acetic acid wash increases cellularity of bloodstained ThinPrep® specimens, prospectively lysing all bloodstained specimens is an unnecessary procedure. Lysing only very heavily bloodstained specimens prior to processing will reduce laboratory workload, costs and the possibility of specimen mix up. Occasionally a retrospective wash may be required but screening staff should be aware that although blood may be present on an unlysed ThinPrep® slide, a lysed slide should not be requested unless there are insufficient numbers of squamous cells present.     

Phagocytic activity of alveolar macrophages in patients with bronchogenic carcinoma

Summary Human bronchoalveolar cells were obtained by lavage during diagnostic fiberoptic bronchoscopy of 21 patients suspected of having lung malignancies. Of these patients 11 were diagnosed as having primary lung cancer (Group I) and included individuals with squamous cell carcinoma, adenocarcinoma, undifferentiated large and oat cell carcinoma at varying locations and TNM stages, 4 patients demonstrated nonprimary metastatic carcinoma (Group II), and 6 patients did not reveal detectable tumors by bronchoscopy or follow-up (Group III) and were included as study controls. We examined the ability of pulmonary alveolar macrophages (PAMs) lavaged from patients in each of the three study groups to phagocytose opsonized sheep red blood cells. Phagocytic activity varied among patients in the same and different study groups; however, no significant differences were observed in the phagocytic or tumoristatic activities of PAMs recovered from tumor-bearing and nontumor-bearing lung regions of the same patient. Moreover, lavage fluids collected from tumor-bearing regions did not suppress the phagocytic activity of PAMs collected from control lungs nor lung regions contralateral to the tumor-bearing lung. The data do not support the view that bronchial neoplasms or their secreted products suppress phagocytic functions of alveolar macrophages.     

Comparison of the pick-and-smear and Saccomanno methods for sputum cytologic analysis

The two methods of preparing sputum specimens for cytologic study, the (fresh) pick-and-smear technique and the (blended) Saccomanno technique, were compared using 249 consecutive specimens. Two slides were prepared for each specimen by each technique. Of the specimens, 103 showed squamous metaplasia, carcinoma in situ or carcinoma. A semiquantitative rating system (0 to 4+) was used to determine the number of diagnostic cells for each method for those 103 cases. More diagnostic cells were found on the Saccomanno preparations (217) than on the fresh preparations (154). There were 121 diagnostic cells in the Saccomanno preparations versus 95 diagnostic cells in the fresh preparations from 63 squamous metaplasias; 7 versus 3 for the preparations from 5 carcinomas in situ; 64 versus 42 from 28 squamous cell carcinomas; 3 versus 1 from 1 large cell undiffernomas; and 12 diagnostic cells in Saccomanno preparations versus 5 in fresh preparations from 3 small cell cancers. Twelve squamous metaplasias, two carcinomas in situ, four squamous carcinomas, one adenocarcinoma and one small cell cancer had no diagnostic cells on the fresh preparations; four squamous metaplasias and one squamous carcinoma had no diagnostic cells on the Saccomanno preparations. More diagnostic information and fewer false-negative results were achieved with the Saccomanno technique.     

Inadequate cervical smears: results of an educational slide exchange scheme

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

Differences between papanicolaou smears with correct and incorrect diagnoses

A case control study of women with carcinoma in situ (CINIII) was undertaken comparing Papanicolaou smears for which false negative reports had been issued with slides for which true positive reports had been made. the number of abnormal cells was the strongest differentiating factor. Where there were less than 50 abnormal cells on the slide, the odds of a false negative report being issued was 23.7 times greater (95% confidence interval 3.7-150) than when there were 200 or more abnormal cells. In false negative slides, the abnormal cells were likely to be not represented throughout the slide, present only as single cells rather than as groups, small in size and with finely granular normochromatic nuclei. We conclude that there are intrinsic differences between true positive and false negative slides. Given these characteristics, rapid rescreening of slides that are considered negative may not be an effective method of reducing the false negative rate.     

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

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

Karyometric image analysis for intraepithelial and invasive cervical lesions

OBJECTIVE: To derive an objective, numeric measure for the progression of intraepithelial and invasive squamous cell cervical lesions. STUDY DESIGN: Thin-layer cervical cytology preparations from colposcopically confirmed normal cervix, low grade squamous intraepithelial lesions, high grade squamous intraepithelial lesions and carcinoma were identified from a cross-sectional study. Fifty-nine cases representing 4 diagnostic categories were selected, and 2,375 nuclei from epithelial cells representative of the diagnostic category were randomly selected for imaging and measurement from these cases. Additionally, 1,378 visually normal appearing intermediate cells from low and high grade squamous intraepithelial lesions, as well as from carcinoma cases, were identified for analysis. The nuclei were quantitatively characterized, and discriminant analyses were performed to derive a progression curve from normal cytology to carcinoma. RESULTS: The lesion signatures show a clear increase in nuclear abnormality with increasing progression. A progression curve was derived based on mean discriminant function scores for each diagnostic category and on the mean nuclear abnormality values for the nuclei in each category, as expressed by their deviation in feature values from normal reference nuclei. CONCLUSION: A numeric assessment of lesion progression for cervical precancerous and cancerous lesions based on karyometric measurements is possible and may provide an objective, precise characterization of each lesion as well as a basis for improved performance in automated cytology-based cervical cancer screening.     

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.     

Objective analysis of stallion sperm motility

An image-analysis system utilizing a microcomputer and CellSoft computer-assisted semen analysis software package was evaluated to assess stallion sperm motility characteristics. Analyses were performed at 37°C on a 6 μl drop of diluted semen placed on a glass slide and covered with an 18 mm² coverslip. Four groups of 25 cells each per slide, four slides per ejaculate and four ejaculates from each of three stallions were analyzed in a nested model. The percentage of motile sperm cells, mean velocity (μm/sec), mean linearity, and mean angular head displacement (μm) were measured. Statistical analysis of variance components showed that within ejaculates, more variation was accounted for in the differences among groups of 25 cells than among slides. Predicted standard deviations calculated for combinations of slides and groups of cells showed that a combination of two slides from which a total of 400 cells were analyzed resulted in a mean intra-assay coefficient of variation (CV) of 5.7% for the four measured variables. The following are individual coefficients of variation: percentage of motile cells (7.8%), mean velocity (6.4%), mean linearity (1.9%) and mean angular head displacement (6.6%). When ejaculate differences were included in the model and predicted standard deviations were calculated for a single ejaculate, the mean inter-assay CV was 9.2%. Mean velocity (6.4%) and mean linearity (4.7%) were more repeatable among ejaculates than either the percentage of motile sperm (14.4%) or angular head displacement (11.2%). It was concluded that this system is precise enough to determine differences in motility characteristics of stallion semen samples.     

Accuracy and perceptions of virtual microscopy compared with glass slide microscopy in cervical cytology

A. Evered and N. Dudding Accuracy and perceptions of virtual microscopy compared with glass slide microscopy in cervical cytology Objective: To evaluate virtual microscopy in terms of diagnostic performance and acceptability among practising cytologists. Methods: Twenty‐four experienced cytologists were recruited to examine 20 SurePath® cervical cytology slides by virtual microscopy. Diagnostic accuracy was compared with glass slide microscopy using an unbiased crossover experimental design. Responses were allocated a score of one for a correct identification of normal or abnormal (borderline/atypical changes in squamous or glandular cells or worse) and a score of zero for an incorrect response (a normal slide reported as abnormal or vice versa). Perceptions of virtual microscopy were assessed by questionnaire analysis. Results: Participants yielded a total of 285 responses for the virtual slide set and 300 for the glass slide set. The approximate time to screen a virtual slide was 18 minutes, compared with 8 minutes or less for a glass slide. Overall there was no significant difference between virtual microscopy and glass slide microscopy in terms of diagnostic accuracy (P = 0.22). Virtual microscopy under‐performed when images were captured over a narrow focal range (P = 0.01). Diagnostic accuracy of virtual microscopy equalled that of glass slide microscopy when participants were able to focus through the full thickness of the slide images (P = 0.07). The most common difficulties experienced by participants with virtual microscopy were freezing of the computer screen during image download, slow response of the computer during slide movement and, in some instances, ‘fuzzy’ images. Cytologists have a strong preference for glass slides over virtual microscopy despite the overall equal diagnostic performance of the two viewing modalities. Conclusions: Diagnostic accuracy of virtual microscopy can equal that of glass slide microscopy. However, without good computer network connections, wide focal range and software that permits effortless navigation across virtual slides, cytologists are unlikely to be convinced of the utility of this technology for cytology screening and diagnosis.     

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

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

Classification of lung carcinoma by means of digital nuclear image analysis

An investigation was performed of the maximum discriminating efficiency for each subgroup of digital nuclear image features and of the overall classification of nuclei from three types of human lung carcinomas in histologic sections: adenocarcinoma, small-cell carcinoma and squamous-cell carcinoma. The results indicate that, for each subgroup of features, the nuclei of the small-cell carcinomas are generally "correctly" classified in a higher percentage (80% to 100%) than are the nuclei of the adenocarcinomas (46% to 74%) and squamous-cell carcinomas (29% to 68%). The discriminant analysis for the overall classification selected features from most of the subgroups, suggesting that it is useful to perform nuclear image analysis with many subgroups having different properties. The overall classifications for the nuclei of the adenocarcinomas, small-cell carcinomas and squamous-cell carcinomas were, respectively, 81.4%, 93.2% and 74.7%. Before this technique can be applied to histopathologic diagnosis, a larger number of unselected lung carcinomas must be evaluated.     

Utility of 2-D and 3-D virtual microscopy in cervical cytology education and testing

OBJECTIVE: To evaluate the effectiveness of 3-D vs. 2-D virtual microscopy as adjuncts to education and assessment in cervical cytology. STUDY DESIGN: Five cervical cytology slides were acquired in 2-D; then the identical area of the slide was acquired in 3-D, resulting in 2 sets of virtual slides for comparison with the original glass slide. Seventy-nine paid volunteer cytologists and cytotechnology students participated. Approximately half were sent the 2-D set of slides via the Web, and the others a 3-D set of slides on a DVD. Evaluators examined the virtual slides and committed to an interpretation. After receipt of the original glass slides, a second interpretation was made, if different from the virtual slide interpretation. RESULTS: Diagnostic accuracy using virtual cytology slides was similar to that for glass slides (94% vs. 96%). There was no difference in diagnostic accuracy between 2-D and 3-D slides (p = 0.28); however, the ability to focus 3-D slides in the z-axis was strongly endorsed by the participants because of the uncertainty and frustration of having some cells out of focus on 2-D virtual slides. CONCLUSION: There was consensus that virtual cervical cytology slides would be a useful augmentation to education and testing.     

Radiation and smoking effects on lung cancer incidence by histological types among atomic bomb survivors

While the risk of lung cancer associated separately with smoking and radiation exposure has been widely reported, it is not clear how smoking and radiation together contribute to the risk of specific lung cancer histological types. With individual smoking histories and radiation dose estimates, we characterized the joint effects of radiation and smoking on type-specific lung cancer rates among the Life Span Study cohort of Japanese atomic bomb survivors. Among 105,404 cohort subjects followed between 1958 and 1999, 1,803 first primary lung cancer incident cases were diagnosed and classified by histological type. Poisson regression methods were used to estimate excess relative risks under several interaction models. Adenocarcinoma (636 cases), squamous-cell carcinoma (330) and small-cell carcinoma (194) made up 90% of the cases with known histology. Both smoking and radiation exposure significantly increased the risk of each major lung cancer histological type. Smoking-associated excess relative risks were significantly larger for small-cell and squamous-cell carcinomas than for adenocarcinoma. The gender-averaged excess relative risks per 1 Gy of radiation (for never-smokers at age 70 after radiation exposure at age 30) were estimated as 1.49 (95% confidence interval 0.1-4.6) for small-cell carcinoma, 0.75 (0.3-1.3) for adenocarcinoma, and 0.27 (0-1.5) for squamous-cell carcinoma. Under a model allowing radiation effects to vary with levels of smoking, the nature of the joint effect of smoking and radiation showed a similar pattern for different histological types in which the radiation-associated excess relative risk tended to be larger for moderate smokers than for heavy smokers. However, in contrast to analyses of all lung cancers as a group, such complicated interactions did not describe the data significantly better than either simple additive or multiplicative interaction models for any of the type-specific analyses.     

Use of automated primary screening on liquid-based, thin-layer preparations

OBJECTIVE: To evaluate the accuracy of the AutoPap System (TriPath Imaging, Inc., Burlington, North Carolina, U.S.A.) (TriPath) in screening AutoCyte PREP liquid-based, thin-layer preparations by comparing the final cytologic diagnoses with instrument slide classification results. STUDY DESIGN: A total of 9,665 AutoCyte PREP thin-layer slides were first independently screened to establish a final cytologic diagnosis (reference diagnosis). The slides were then processed on the AutoPap System. Each slide successfully processed was reported into result categories. The generated report gave a ranking score for each slide designated for "review." Slides designated "no further review" (NFR) were also listed in the report. The reported results were then compared to the reference cytologic diagnoses. RESULTS: Of 9,665 slides initially submitted to the AutoPap, 8,688 (90.8%) were qualified for scanning, and 884 (9.2%) were definitely classified as process review or rerun and excluded from the study. Of high grade squamous intraepithelial lesions and greater (HSIL+), 85.2% were ranked in the first rank, 12.7% in the second, one (2.1%) in the third, none in the fourth and fifth and none in the NFR category. Of low grade squamous intraepithelial lesions, 47.4% were ranked in the first rank, 20.8% in the second, 10.6% in the third, 10.1% in the fourth, 5.3% in the fifth and 5.8% in NFR. Of atypical squamous cells of undetermined significance and atypical glandular cells of undetermined significance, 53.6% were ranked in the first rank, 22.5% in the second, 12.4% in the third, 5.4% in the fourth, 3.8% in the fifth and 2.3% in NFR. Considering a cutoff value at < or = 3rd rank, 84% of cervical abnormalities (RR 6.52, 95% CI 4.96-8.66) and 100% of HSIL+ were identified. CONCLUSION: The AutoPap demonstrates a high capability for detecting cervical abnormalities on AutoCyte PREP thin-layer slides. HSIL+ was associated with the highest instrument scores.     

Atypical squamous cells as a diagnostic pitfall in pulmonary Wegener's granulomatosis. A case report

BACKGROUND: Wegener's granulomatosis (WG) is characterized by systemic, necrotizing, granulomatous inflammation accompanied by vasculitis. It classically involves the triad of the upper respiratory tract, lungs and kidneys. Isolated pulmonary lesions of WG may present in some patients as pulmonary masses, simulating neoplasms. The features of WG can be suggested by cytologic study. Atypical epithelial cells associated with WG have previously been reported as a cause of a false positive diagnosis of bronchoalveolar carcinoma. CASE: In this case the cytologic findings included atypical squamous cells in a background of acute, chronic and granulomatous inflammation. In several respiratory specimens the atypical squamous cells were incorrectly interpreted as diagnostic of squamous cell carcinoma. The correct diagnosis of WG was confirmed with open lung biopsy, which demonstrated necrotizing granulomatous inflammation with geographic necrosis and associated vasculitis. CONCLUSION: Markedly atypical squamous cells mimicking squamous cell carcinoma can be found accompanying the inflammatory process associated with WG and are a possible diagnostic pitfall. The possibility of WG as well as other inflammatory processes should always be considered in the differential diagnosis of squamous cell carcinoma of the lung. This case is the only reported case of WG in which atypical squamous cells were a diagnostic pitfall, initially suggesting a diagnosis of squamous cell carcinoma.     

A new procedure to study the perceptual world of animals with sensory reinforcement: Recognition of humans by a chimpanzee

A female chimpanzee touched a button to produce colored slides of pictures. Slides were present as long as she kept touching the button. Repeated touch within 10 sec after the previous release produced the same slides again. The slide was changed when 10 sec passed after she released the button. The duration of a touching response and the interval between the responses were calculated for each of 100 slides. The data for each slide were plotted on the two-dimensional space constructed with response duration and response interval. A clear differentiation of distribution on this space was found between slides with humans and those without humans. The result demonstrated that the chimpanzee recognized humans as a category, as well as that this procedure is effective for the study of the perceptual world of animals based on the reinforcing function of stimuli.     

Acetic acid recovery of gynecologic liquid-based samples of apparent low squamous cellularity

OBJECTIVE: To characterize cervicovaginal cytology samples with < 5,000 squamous cells on the initial ThinPrep slide (Cytyc Corp., Boxborough, Massachusetts, U.S.A) and to attempt sample recovery using acetic acid. STUDY DESIGN: Cervicovaginal cytology samples with <5,000 squamous cells on the original ThinPrep slide and residuum were reprocessed by adding 3 mL of 3:1 CytoLyt (Cytyc)/glacial acetic acid with production of a second slide. Both slides were reviewed for squamous cell quantitation and the presence of background material and abnormal cells. RESULTS: From a total of 1,833 cases, 147 (8.0%) were identified for reprocessing; 71 (48.3%) were grossly bloody and 58 (39.4%) grossly cloudy. Reprocessing resulted in a second slide with > 5,000 squamous cells in 116 (78.9%) cases and was most effective on cloudy samples (89.7% recovery) and bloody samples (71.8% recovery). Abnormal cells were identified in 13 (8.9%) reprocessed samples. In all but 2 cases the abnormal cells were present on the initial slide and demonstrated the same degree of abnormality as the reprocessed slide but were fewer in number. CONCLUSION: Acetic acid recovery increases squamous cell recovery when initially inadequate, reducing the number of unsatisfactory cases and in rare cases identifying a cytologically significant lesion not apparent on the original slide.     

Inverted papilloma of the nasal cavity presenting with massive amounts of squamous metaplastic cells in sputum. A case report

BACKGROUND: Squamous metaplasic cells are rarely seen in sputum of female nonsmokers. CASE: A 47-year-old female nonsmoker presented with massive amounts of squamous metaplasic cells in sputum and an elevated level of squamous cell carcinoma (SCC) antigen in serum present for months, while no causative lesion was detected either by lung computed tomography or bronchoscopy. The patient was eventually diagnosed as having inverted papilloma in the right nasal cavity. Resection of the tumor brought about disappearance of squamous metaplastic cells in sputum and return of serum SCC antigen to the normal range. CONCLUSION: This case clearly demonstrates that squamous metaplastic cells in sputum can originate in lesions in the nasal cavity, although they are rare. It should be kept in mind that the nasal cavity is a potential site producing squamous metaplastic cells in sputum.