Vaginal intraepithelial neoplasia and the Pap smear

OBJECTIVE: To assess the sensitivity of the vaginal smear cytologic examination in detecting vaginal intraepithelial neoplasia (VAIN) and to evaluate the cytologic findings of cases of VAIN. STUDY DESIGN: Cases with a histologic diagnosis of VAIN were identified from the Barnes-Jewish Hospital South and North Campus over a period of five and nine years, respectively. Only posthysterectomy patients with a tissue biopsy diagnosis of VAIN and with a vaginal smear obtained within three months of the biopsy were included in the study. Pertinent clinical information was obtained by reviewing the medical records. Two pathologists reviewed the pathologic samples. RESULTS: Thirty-five vaginal smears from 31 posthysterectomy patients were included in the study. The mean age was 57 years (range, 29-84). The cytologic diagnoses of smears from patients with VAIN included: high grade squamous intraepithelial lesion (19 cases), low grade squamous intraepithelial lesion (10 cases), atypical squamous cells of uncertain significance (5 cases) and negative for malignancy (1 case). CONCLUSION: The sensitivity of the vaginal smear cytologic examination in detecting VAIN is 83%. Obscuring inflammation contributed to false negative diagnoses in two cases.     

Goblet-like cells in atrophic vaginal smears and their histologic correlation. Possible confusion with endocervical cells.

The occurrence and origin of goblet-like cells seen between clusters of parabasal cells in atrophic vaginal smears were investigated. The goblet-like cells were cytologically identified in the vaginal smears from 23 (19.2%) of 120 patients whose smears showed an atrophic pattern, but without any inflammatory, dysplastic or malignant changes. Histologically, these cells were found in sections from 6 (18.8%) of 32 elderly women with atrophic vaginal epithelium. The goblet-like cells were situated among the squamous cells of the upper layer of the atrophic squamous epithelium from the vagina to the portio. These goblet-like cells in atrophic smears were initially misinterpreted as endocervical cells, which are regarded as a marker of smear adequacy in the cytologic screening for cancer of the uterine cervix. The correct interpretation of these goblet-like cells in smears from postmenopausal and elderly women is thus obviously important in assessing the adequacy of the sample for the detection of abnormal cells.     

Longitudinal studies on the phenomenon of postmenopausal estrogen production

Longitudinal studies on the phenomenon of postmenopausal estrogen pr oduction are presented. Cytohormonal screening was repeated after 1-4 years in 5633 women. The outcome of the 2nd smear was determined by the cytologic characteristics of the 1st smear and by body weight. A thin woman with an atrophic 1st smear had only 4.8% probability of showing an estrogenic 2nd smear, whereas a grossly obese woman with an estrogenic 1st smear had a 26.2% chance of showing an estrogenic 2nd smear. Series of 8-12 cytologic smears were studied within 2 months in 80 women. Evidence indicated that the phenomenon of postmenopausal estrogenic smears tended to be continuous. 24-hour urine specimens from 100 normal women were analyzed and the cytologic-biochemical relationships were studied. Persistent estrogenic smears predicted higher excretion of estrone and estriol and slightly lower excretion of androsterone and etiocholanolone.     

The effect of delivery on regression of abnormal cervical cytologic findings

The purpose of this study was to determine whether abnormal antepartum cervical cytologic findings result in differing postpartum regression rates. Between 1993 and 2000, 107 pregnant women with antepartum abnormal cervical cytologic findings were identified. Papanicolaou smear data were separated into three groups by use of the CIN classification system. Postpartum regression rates of antepartum Papanicolaou smears were analyzed six months after delivery. Normalization of Papanicolaou smears in the postpartum period were observed in 50 of 107 women (46.7%). Regression of cervical cytologic findings was noted in 61 of 107 women (57%). Respectively, persistence of Papanicolaou smear was noted in 43 of 107 patients (40%). Only 3 of 107 (3%) antepartum findings progressed after delivery. Desquamation of the cervical epithelium or enhancement of a localized reparative immunologic response after vaginal delivery could play an important role in the spontaneous regression of cervical dysplasia in the postpartum period.     

Estimating the sensitivity of cervical cytology: errors of interpretation and test limitations

The objective of this study was to estimate: (i) the sensitivity of cytologists in recognizing abnormal smears; (ii) the sensitivity of cervical cytology as a method of detecting abnormal smears among those obtained in the presence of cervical intraepithelial neoplasia (CIN). Study subjects were 61 women with a histologically confirmed CIN identified through colpohistological and cytologic screening. For objective (i) new smears were taken from study subjects just before treatment, mixed with routine preparations, interpreted by unaware cytologists and then blindly reviewed by a group of three expert supervisors, who reached a consensus diagnosis. Cytologists classified as positive for squamous intraepithelial lesion (SIL) 30 of the 34 smears judged as positive by supervisors (100% of smears classified as high-grade and 67% of smears classified as low-grade SIL by the supervisors). Our approach, based on creating a set of smears with a high a priori probability of being positive, proved to be an efficient way of estimating errors of interpretation. For objective (ii), smears taken at the moment of diagnosis, just before biopsy, were also reviewed by the same supervisors. These CIN cases were identified among asymptomatic women independently of cytological findings and results are therefore not subject to verification bias. Among the 33 histological CINII/III, four (12%) smears had no atypical cells (three negatives and one unsatisfactory) at review. The same proportion was 26% (four negatives and one unsatisfactory) among the 19 histological CINI. No significant differences in smear content were found between the seven ‘false negatives’ and a sample of ‘true positives’ and ‘true negatives’ for a number of formal adequacy criteria (including presence of endocervical cells). Strong differences were found between positive smears taken just before biopsy and those taken just before treatment (in 11 women the first smear only was positive, while the opposite was never observed), suggesting an effect of punch biopsy in removing lesions.     

Accuracy of thin-layer cytology in patients undergoing cervical cone biopsy

OBJECTIVE: To compare the accuracy of thin-layer cytology with Autocyte PREP (TriPath Imaging Inc., Burlington, North Carolina, U.S.A.) with conventional smears in 500 women undergoing cervical cone biopsy. STUDY DESIGN: The study was performed among 500 consecutive women presenting for cone biopsy for high grade cervical intraepithelial neoplasia (CIN) on biopsy in 350 (70%) and discrepant cytology/colpohistology in 150 (30%). Before performing a cone biopsy, two cervical samples were collected for conventional smears and thin-layer cytologic slides, with randomization of the order. Conventional smears were stained and diagnosed at Pasteur Cerba, while thin-layer cytologic slides were processed at a local TriPath office (Meylan, France) and sent in a masked fashion for screening at Pasteur Cerba. Any slides initially read as normal were reviewed again and reported without knowledge of the other cytologic or cone biopsy data. The final cytologic diagnoses for the two methods were compared with histopathology of the cone biopsy. RESULTS: The conventional smear was unsatisfactory in 58 (11.6%) of cases, while there were 4 (0.8%) unsatisfactory thin-layer cytologic slides (P < .001). Endocervical cells were missing from 31 (6.2%) of conventional smears and 34 (6.8%) of thin-layer cytologic slides. For the pooled data, sensitivities of conventional smear and thin layer for detecting high grade CIN (0.82% and 0.86%, respectively) were similar as were specificities (0.40% and 0.43%, respectively). When first samples were compared, the sensitivities of the conventional smear and thin layer for high grade CIN were 0.79% and 0.89%, respectively (P = .02), with corresponding specificities of 0.41% and 0.36% (P < .01). CONCLUSION: When controlled for sample order, the sensitivity of thin-layer cytology for detecting high grade CIN was significantly higher than that of conventional smears in patients with previous abnormal cytology, but at the expense of specificity.     

The Irrigation Smear—A New Cytodiagnostic Technique for the Detection of Cancer of the Uterine Cervix

Using the Davis cytopipette, cytologic smears were prepared from 2014 patients; 1367 of these specimens were obtained by the patients themselves. The series included 57 cases of carcinoma or atypia of the cervix, and 50 (88%) of these cases were found to have abnormal cells in the irrigation smear.Cytopipette samples were obtained by a nurse from 647 Eskimos, but cell preservation in this group was not satisfactory because of a delay of several weeks in preparing the smears. Accurate results depend also on specific training of the personnel reading the smears because fewer cells may be present in these smears than in cervical scrape smears.The irrigation smear is recommended as a reasonably accurate method of screening women for cancer of the cervix if they are not being examined regularly by the cervical scrape method. Hospital admissions of females may be a fruitful source of such cases.     

Abrasive bronchial brushing cytology. A preliminary study of 200 specimens for the diagnosis of neoplastic and nonneoplastic bronchopulmonary lesions

Two hundred subjects with chronic respiratory symptoms with a suspicion of malignancy were selected for bronchial brushing cytology. Prior sputum examination had shown malignant squamous cells in two cases only. The cytologic appearances of the brushing smears were divided into five categories: 41 (20.5%) smears with positively malignant cells; 20 (10%) smears predominantly showing chronic inflammatory features; 31 (15.5%) smears with mainly acute inflammatory changes; 60 (30%) smears with normal cytologic features; and 48 (24%) smears unsatisfactory for cytologic interpretation. Thirteen patients with a positive cytology had a positive tissue biopsy for malignancy. Among the group with chronic inflammatory changes, acid-fast bacilli were identified in nine cases, and one smear showed frank tuberculous granuloma. In the unsatisfactory group, two cases showed malignant cells in the postbrushing sputum. There was one false-negative report for malignancy in the entire study. This study confirms the sensitivity and accuracy of bronchial brushing cytology in the diagnosis of various bronchopulmonary lesions, especially malignancy and pulmonary tuberculosis, in India.     

Analysis of cervical smears obtained within three years of the diagnosis of invasive cervical cancer

The cytologic histories of 376 women presenting with invasive carcinoma of the cervix were analyzed. In total, 202 (53.7%) of these women had had 355 smears taken during the three years preceding presentation. All 320 smears with an original cytologic diagnosis of less than cancer were reviewed. The original cytologic diagnosis was low in 95 (30.6%) of 310 adequate smears. Originally, 96 (30.9%) of the adequate smears were evaluated as negative; at review, only 55 (17.5%) of the adequate smears were evaluated as negative. Comparing the review diagnoses to the 355 total smears, the rates of negative smears were 13.5% (42 of 310) for squamous-cell carcinoma, 30.0% (12 of 40) for adenocarcinoma and 20.0% (1 of 5) for adenosquamous carcinoma (P less than .05). The cellular composition of the smear was significantly related to the cytologic detection of abnormalities: endocervical cylindrical and/or metaplastic cells were seen in only 45.5% of smears diagnosed as negative, but in 84.4% and 97.8% of smears diagnosed as atypia and cervical intraepithelial neoplasia, respectively P less than .00001). Smears without endocervical cells should be considered inadequate and should be repeated.     

Evaluation of p16INK4a in cervical lesion of premenopausal and postmenopausal women

Pap smears of postmenopausal women are often misdiagnosed because of the difficulty in distinguishing atrophic epithelial cells groups only by morphological criteria. In this study we investigated the diagnostic application of immunocytochemical staining of p16INK4a on conventional Pap smear. A total of 137 cervical specimens were enrolled in this study, of which 77 and 60 cervical smears were taken from premenopausal and postmenopausal women, respectively. Two cervical smears were taken simultaneously in 68 women, one for conventional cytology and the other for immunostaining. Additional 69 cervical smears were taken from the archive, decolorized and then used for immunostaining. In premenopausal women 1 out of 14 (7.1%) with negative cytology, 7 out of 24 (29.2%) with low grade squamous intra-epithelial lesion (LSIL), all 35 (100%) with high grade squamous intraepithelial lesion (HSIL) and all 4 (100%) with squamous cell carcinoma (confirmed by histopathology) had positive staining to p16INK4a. In postmenopausal women p16INK4a positivity was observed in 4 out of 7 (57.1%) cases of LSIL, 12 out of 14 (85.7%) cases of HSIL and all 4 out of 5 (80%) different cases of carcinoma (1 cervical adenosquamous carcinoma and 3 cervical squamous cell carcinoma in situ confirmed by histopathology), but none of 34 smears with normal cytology. Twenty smears with normal cytology chosen for the negative control in this study were from the group of postmenopausal women and were as expected negative for p16INK4a immunostaining. In the group of postmenopausal women, 16 out of 60 (26.7%) cases the cytological diagnosis was established on the basis of pl6lNK4a immunostaining as being HSIL. From our preliminary study on a limited number of samples, we can however conclude that pl6INK4a immunostaining is a very useful tool for cytological diagnosis enabling to distinguish HSIL from normal, reactive or inflammatory changes.     

The post-LLETZ cervical smear: influence of time interval from LLETZ

OBJECTIVE: To determine the effect of the time interval between large loop excision through the transformation zone (LLETZ) and the first subsequent cervical smear on the adequacy of the smear for cytologic interpretation and cytologic abnormality rates. STUDY DESIGN: A retrospective, case-note analysis of women attending a colposcopy clinic between May 1, 1999, and March 31, 2002, who had high grade histologic lesions on their LLETZ biopsy, irrespective of the referral indication. RESULTS: A total of 771 women were included in the study. Negative smears were reported in 639 (82.9%); 82 (10.6%) were abnormal and 50 (6.5%) unsatisfactory. The post-LLETZ smear was performed at a median interval of 105 days (range, 48-829). A univariate logistic regression analysis did not reveal any relationship between the rate of unsatisfactory or abnormal smears and the interval since having LLETZ (p = 0.935). CONCLUSION: These data do not support the traditionally held concept that performing the post-LLETZ smear before 6 months increases the rate of unsatisfactory or abnormal smears.     

Significance of AGUS Pap smears in pregnant and postpartum women

OBJECTIVE: To study the clinical significance of atypical glandular cells of undertermined significance (AGUS) in pregnant and postpartum women. STUDY DESIGN: We evaluated 35 women who were pregnant (30) or within three months postpartum (5) and had a cytologic diagnosis of AGUS. Twenty-seven (77%) patients had follow-up: 17 (63%) patients underwent colposcopic examination and biopsy, and 10 (37%) had repeat Pap smears. Eight patients were lost to follow-up. RESULTS: Five (29.4%) patients had a squamous intraepithelial lesion (SIL), including three high grade and two low grade, on subsequent biopsy. The remaining (70.6%) patients had benign pathology, which included 5 chronic cervicitis, 4 endocervical and/or endometrial polyps, 2 Arias-Stella reaction and 1 microglandular hyperplasia. Among the patients with repeat Pap smears, two had persistent AGUS/atypical squamous cells of undetermined significance, the remaining cases were within normal limits. CONCLUSION: Pregnancy-related changes may present with glandular atypia. In addition, about one-third of pregnant and postpartum women with a diagnosis of AGUS had SIL on subsequent biopsy; that rate is similar to that in nonpregnant women. Therefore, pregnant women with a cytologic diagnosis of AGUS should be followed closely.     

Contribution of exfoliative cytology to the diagnosis of laryngeal lesions

OBJECTIVE: To estimate the diagnostic accuracy and reliability of exfoliative laryngeal cytology. STUDY DESIGN: Over three years (1996-1999) cytologic smears were obtained from clinically suspicious laryngeal lesions during laryngoscopy in a total of 31 selected patients (28 males and 3 females with an age range from 28-90 years). The cytologic diagnoses were analyzed and correlated with the histologic and final clinical diagnoses in 17 and 14 cases, respectively. Cytologic identification of the exact histologic type of the lesion was evaluated in 17 patients from whom both cytologic smears and biopsy material were obtained. RESULTS: The overall specificity was 100%, with no false positive diagnoses. The overall sensitivity was 93.3%, with one false negative cytologic diagnosis, in a case of non-Hodgkin's lymphoma. Cytohistologic correlation showed complete agreement between cytologic and histologic diagnoses in five of six benign lesions, in four cases of dysplasia and in six cases of squamous cell carcinoma. The overall diagnostic accuracy of cytology was 96.7% CONCLUSION: Exfoliative cytology by the smear technique is a reliable and accurate method in clinically suspected laryngeal lesions. Moreover, exfoliative cytology may be applied as the only alternative diagnostic method, especially in elderly patients with coexistent cardiorespiratory problems, when biopsy is not advisable or indicated.     

Efficacy of Ki-67 antigen staining in Papanicolaou (Pap) smears in post-menopausal women with atypia—an audit

In cervical smears from post-menopausal women with mucosal atrophy it can be difficult to distinguish atrophic epithelial cell groups from neoplastic cell groups on cytomorphological criteria only. The consequence of post-menopausal atypia is that the woman is referred for a repeat smear after local oestrogen treatment or for colposcopy. We investigated whether immunocytochemical expression of Ki-67 (MIB-1) on the primary Papanicolaou-stained smear could be of any diagnostic help. Our data showed that negative Ki-67 expression is a very reliable indicator of a normal atrophic cell pattern, and by using this method on the original smear we were able to reduce the false-positive cytologic diagnoses by 86%.     

Microfilariae of Wuchereria bancrofti in cytologic smears

Microfilariae of Wuchereria bancrofti were observed in cytologic material in 35 cases. The material included cervicovaginal smears (17 cases), effusions (14), urine (2), bronchial washings (1) and ovarian cyst fluid (1). The initial diagnosis was made from the cytologic smear in all cases; none had clinical filariasis. Symptomatic vaginal bleeding in 9 of the 17 cases with microfilaria-positive cervicovaginal smears was reflected in the large numbers of red blood cells found in the smear. Blood eosinophilia was present in 11 of 19 cases investigated. Eosinophils were seen in the smears in 20 cases. In the majority of the cases of effusions with microfilariae the effusions were malignant. Significant adherence of inflammatory cells and macrophages to microfilariae was present in 7 of the 35 cases. The significance of these findings is discussed.     

Review of cervical smears from 76 women with invasive cervical cancer: cytological findings and medicolegal implications

OBJECTIVE: To review cervical smears from 76 women which were taken prior to the diagnosis of invasive cervical cancer and to determine the appropriateness of the cytology reports issued on the smears. METHODS: Cervical smears, clinical records, cervical smear history and cytology reports from 76 women with invasive cervical cancer were reviewed. After microscopic review of the cervical smears, the cases were divided into two groups: Group 1 comprised 50 women who were found to have had at least one false-negative (F/N) smear report prior to the diagnosis of invasive cervical cancer. Group 2 comprised 26 women for whom no evidence of F/N reporting was found. RESULTS: A total of 209 cervical smears from the 50 women in group 1 were available for review (range 2-12 smears per woman); 100 of the 209 smears were considered to have been reported appropriately. Ninety-seven smears which had been reported originally as negative or inadequate were found, on review, to contain numerous severely dyskaryotic cells and were reclassified as F/N smears. All of the 50 women had at least one F/N smear and 29 had two or more. Twelve smears from eight women contained only a few (<200 severely dyskaryotic cells). Forty women developed invasive squamous carcinoma and 10 developed invasive adenocarcinoma. The stage at diagnosis ranged from 1A to stage 4. Seventy-one smears from the 24 women in group 2 were available for review (range 1-15 smears per woman). In two cases included in group 2, no smears were provided for review as the smears had been lost or mislaid. Review of the 71 smears confirmed the accuracy of the original cytological classification of the smear. Nineteen women were diagnosed with squamous cancer, two microinvasive cancer, one glassy cell, two adenocarcinomas, and one with adenosquamous carcinoma. One women was found to have an embryonal rhabdomyosarcoma of the corpus uteri involving the cervix. DISCUSSION/CONCLUSION: The medicolegal implications are discussed in the light of the above findings. Evidence of breach of duty of care was presented in all 50 cases in group I although causation was not established in every case. There was no evidence of failure of duty of care in terms of the standard of the cervical cytology reports issued or standard of clinical management in 17 of the 26 cases in group 2. However, in seven of the 26 cases in group 2, clinical management of the case was substandard due to failure to investigate symptoms of irregular bleeding regardless of a negative cytology report (two cases), failure to act upon a suspicious smear report or consecutive inadequate smear reports (two cases), failure of follow-up after treatment of CIN3 (two cases) and histological misdiagnosis (one case).     

Use of the Cytobrush for cervical sampling after cryotherapy

The presence of endocervical cells in routine gynecologic smears (prepared from spatula and cotton swab samples) and Cytobrush smears was analyzed in 52 patients with a history of prior cryotherapy. These cases represented 11% of the 491 women evaluated using both techniques between August 1, 1987, and January 31, 1990. The routine smear contained endocervical cells in 25 (48%) of the 52 cases while the Cytobrush smear contained endocervical cells in 49 (94%) of the cases. The use of the Cytobrush for cervical cytologic screening thus appears to be of value in patients with a prior history of cryotherapy, which frequently renders the transformation zone less accessible to routine sampling.     

Evaluation of pregnancy-related cells in endometrial cytology

OBJECTIVE: To determine the significance of pregnancy-related cells in endometrial smears. STUDY DESIGN: Pregnancy-related cells in 4429 endometrial smear samples were retrospectively analyzed and evaluated for clinicopathologic and cytomorphologic features. RESULTS: Of the 4429 endometrial smears taken for cancer screening, pregnancy-related cells were detected in 12 cases (0.3%). They were estimated cytologically as negative or suspicious and confirmed as cases ofspontaneous abortion (8 cases), placental site nodule (3 cases), and partial hydatidiform mole (1 case). Decidual cells were observed in all cases, and some of these showed atypia. Trophoblasts were observed in 5 (41.7%) of the 12 cases. Syncytiotrophoblasts were observed in 1 case (8.3%) and nonsyncytiotrophoblasts in 5 (41.7%) of the 12 cases. Pregnancy-related cells were observed in an endometrial smear in 7 cases; other cases were missed during cytologic examination and were retrospectively identified. CONCLUSION: Pregnancy-related cells are likely to be missed because they are difficult to identify or are surrounded by a cluster of endometrial cells. The decidual cell is a key cell for the cytologic diagnosis of pregnancy-related cells. Determining the existence of pregnancy-related cells in endometrial smears is important for the further assessment of patients and the differential diagnosis of several endometrial lesions.     

Value of histiocyte detection in Pap smears for predicting endometrial pathology. An institutional experience

OBJECTIVE: To determine the clinical implications of the finding of histiocytes in Pap smears in 1 patient population. STUDY DESIGN: The medical records and Pap smears which the presence of histiocytes was mentioned in the diagnosis between August 1996 and August 2001 were reviewed in conjunction with follow-up surgical findings. The positive predictive value (PPV) for significant endometrial pathology for the isolated finding of histiocytes on Pap smear was determined. RESULTS: Of the 238,225 women screened over a 60-month period, 325 were reported to have histiocytes in their Pap smears. Of them, 238 (73.2%) had subsequent endometrial sampling, hysterectomy or both, and follow-up Pap smears. Two hundred seven smears (87%) failed to disclose endometrial pathology. Thirty-one cases (13%) resulted in significant histopathologic findings, including 12 uterine malignancies, 8 endocervical polyps, 7 endometrial polyps, 2 submucosal leiomyomata, 1 simple hyperplasia without atypia and 1 case of tamoxifen-related changes. Upon review of the clinical records, 58% (18/31) of those patients had other significant clinical and/or cytologic findings. Five of the 18 patients (27.8%) had associated postmenopausal bleeding, 11 had additional abnormal Pap smear findings (atypical glandular cells, 6/18, or 33.3%; endometrial cells, 5/18, or 27.8%), and another 2 had both postmenopausal bleeding and atypical glandular cells (2/18, or 11.1%). The PPV for significant uterine pathology for women with the isolated finding of histiocytes on a Pap smear was 5.5% and 60% with additional clinical and/or Pap smear findings. The PPV for endometrial cancer was 1.3% in women with the isolated finding of histiocytes on a Pap smear but 20% for women with histiocytes and additional clinical/or Pap smear findings. CONCLUSION: Based on the findings of this study and recently published data, we conclude that the isolated finding of increased histiocytes in the absence of postmenopausal bleeding, endometrial cells or atypical glandular cells on a Pap smear is a poor indicator of uterine disease.     

DNA-cytometric diagnosis of prospective malignancy in borderline lesions of the uterine cervix

Interactive DNA cytometry was used for the diagnosis of prospective malignancy in 48 smears with borderline lesions (mild and moderate dysplasias) of the uterine cervix. In addition, 183 smears with benign squamous epithelia, 38 with carcinoma in situ and 7 with invasive squamous carcinoma were also measured. Nuclear Feulgen-DNA measurements were performed using various methods, and the resulting data were analyzed by an algorithm for a DNA-cytophotometric diagnosis of malignancy. The results were compared with the data on follow-up and subsequent histologic studies in these cases. There was no false-positive diagnosis in the 183 benign smears and only 1 false-negative diagnosis in the 76 histologically proven squamous-cell carcinomas, which yields a specificity of 100% and a sensitivity of 98.6%. The sensitivity for the detection of subsequent histologically proven malignancy in cases with cytologically mild or moderate dysplasia amounted to 97%. In 13 borderline cases, there was a mean interval of 21 months between the taking of the cytologic smear on which the DNA diagnosis of malignancy was made and the date on which the histologic confirmation of malignancy was made. In 17% of the cytologically dysplastic cases, the DNA diagnosis of malignancy was not verified by subsequent histologic investigation. These results indicate that interactive DNA cytometry is able to detect prospective malignancy in smears from borderline lesions of the uterine cervix with a high sensitivity.