Influence of the histologic and cytologic grade and the clinical and postsurgical stage on the rate of endometrial carcinoma detection by cervical cytology

The influence of postsurgical stage, histologic grade and cytologic grade of the tumor on the rate of detection of endometrial carcinoma by cervical smear was examined in a retrospective study. Cervical smears from 220 patients with endometrial carcinoma seen in the years between 1965 and 1981 were reevaluated for the presence of normal, suspicious or frankly malignant endometrial cells. The smears were positive in 33.2% of the patients, suspicious in 25.5% and negative in 40%. In three cases (1.4%), the smear was technically inadequate. Positive or suspicious smears indicated the presence of a higher grade as well as a higher stage of the lesion. In this material, the presence of normal endometrial cells as an indicator of endometrial disease, as emphasized in the literature, proved useless since normal endometrial cells without accompanying malignant cells were not seen in a single case. It appears that the reason for the lower rate of detection of low-grade endometrial carcinoma is the complete absence of any exfoliation in these lesions.     

Origin of adenocarcinoma cells observed on cervical cytology

OBJECTIVE: To clarify the ratio of diseases suspected when malignant glandular cells are observed on cervical cytology. STUDY DESIGN: Seventy cases of cervical adenocarcinoma/adenosquamous carcinoma, 207 cases of endometrial adenocarcinoma, 7 cases of tubal adenocarcinoma and 83 cases of ovarian adenocarcinoma were reviewed. The positive rate in cervical cytology performed 3 months before surgery was calculated. Based on the positive rate for each entity and the number of cases treated in the previous 10 years, we estimated the incidence of disease responsible for malignant glandular cells on cytology. RESULTS: The positive rate was 93% in cervical adenocarcinoma/adenosquamous carcinoma, 45% in endometrial adenocarcinoma, 14% in tubal adenocarcinoma and 6% in ovarian adenocarcinoma. These positive rates and case numbers at our institute indicated the percentage of suspicious diseases to be 38% for cervical aaenocarcinoma/adenosquamous carcinoma, 53% for endometrial adenocarcinoma, 1% for tubal adenocarcinoma and 8% for ovarian adenocarcinoma. CONCLUSION: When a cytologic specimen suggested the existence of adenocarcinoma, the most probable disease was endometrial adenocarcinoma, and the second was cervical adenocarcinoma/adenosquamous carcinoma. Adnexal malignancies were responsible in 9% of cases. In the case of positive cervical cytology suggesting adenocarcinoma, the ratio of suspicious diseases is as valuable as the cytologic findings for the differential diagnosis.     

Basement membrane material and tigroid background in a fine needle aspirate of clear cell adenocarcinoma of the cervix. A case report

BACKGROUND: Although cytologic findings of clear cell adenocarcinoma of the female genital tract have been reported sporadically, the background on the smear has received little attention. CASE: A 16-year-old female had a large, necrotic mass in the cervix. As cervical brushing cytology and a punch biopsy of the mass could not make a definitive diagnosis, fine needle aspiration cytology was performed from the mass. The smears revealed loose, three-dimensional clusters and sheet arrangements of atypical cells. Dispersed atypical cells were also seen. The atypical cells were large and had abundant, weakly stained cytoplasm and round or oval nuclei with large nucleoli. There were a few tumor cells with clear cytoplasm and distinct cell borders in Papanicolaou-stained smears. The background in Diff-Quik-stained smears revealed a tigroid background and basement membrane material. CONCLUSION: The malignant tumor, revealing both a tigroid background and basement membrane material, seems to have been clear cell adenocarcinoma. Both features are diagnostic clues to clear cell adenocarcinoma in the female genital tract. Our case indicates that aspiration cytology is also an effective method of diagnosing a cervical tumor when the tumor is polypoid and the surface is extensively necrotic.     

Clinical significance of atypical glandular cells by the 2001 Bethesda System in cytohistologic correlation

OBJECTIVE: To evaluate incidence, cytology findings and pathology outcome of atypical glandular cells (AGC) in Pap smears according to the 2001 Bethesda criteria. STUDY DESIGN: From 103,073 consecutive Pap smears, 113 (0.1%) AGC cases were identified. Of these, 91 (80%) had adequate histologic evaluation included in this study. RESULTS: Abnormal histology findings were seen in 38 patients (42%). Final pathology results revealed 14 endometrial adenocarcinomas, 5 endocervical adenocarcinomas, 1 cervical squamous cell carcinoma, 1 endometrial stromal sarcoma, 6 other malignancies, 4 endocervical adenocarcinomas in situ, 4 cases ofendometrial complex byperplasia, 1 case of endocervical glandular dysplasia and 2 cases of cervical intraepithelial neoplasia 3 with glandular involvement. Women with AGC, favor neoplasia, were more likely to have significant pathology than those with AGC, not otherwise specified, 74% vs. 33% (p = 0.002). Some characteristic background cytologic findings were also noticed in most cases of endometrial, fallopian tube and endocervical adenocarcinoma. CONCLUSION: A diagnosis of AGC is more clinically significant by the 2001 Bethesda System, especially the "AGC, favor neoplastic" category. Some background cytologic features are important because they are indicators of malignancy.     

Endocyte endometrial smears in the cytodiagnosis of endometrial carcinoma

The cytologic diagnosis of endometrial cancer using material obtained with the Endocyte endometrial sampler was assessed for 874 patients. The samples obtained were smeared directly on slides for fixation and staining; the smears were more difficult to assess than cervicovaginal smears, however, due to the presence of blood, the small size and density of the cells and the flattened three-dimensional architecture of the tissue fragments obtained. Only 8.2% of the samples were classified as inadequate; repeat sampling in some of those cases produced diagnostic material. All 12 cases of carcinoma (including one case in a woman less than 40 years of age) were diagnosed by cytology as malignant; however, the original cytologic sample in one of those cases was inadequate. For the diagnosis of benign versus malignant, cytology had a sensitivity of 92%, a specificity of 100% and predictive value of 100%. Cytology also diagnosed as suspicious the smears from 5 of 13 cases of endometrial hyperplasia and 2 of the 9 cases of endometrial polyps. The cytologic findings for benign and malignant samples are described and illustrated in detail. Relative to other endometrial sampling devices, the Endocyte is inexpensive and was easily used by the gynecologist and well tolerated by the patients, with no complications and minimal discomfort.     

Cytologic detection of cervical and endometrial carcinoma with other genital tract involvement

OBJECTIVE: To investigate the possibility of a correct cytologic diagnosis of cervical and endometrial carcinoma with other genital organ involvement. STUDY DESIGN: From uteri removed during hysterectomy due to cervical (33 cases) and endometrial (44 cases) cancer, samples were taken by cytobrush or spatula from the ectocervix, endocervix and endometrium of uteri opened longitudinally. Smears and cytosediments were stained by the Papanicolaou polychrome method. Moreover, acid beta-galactosidase activity was demonstrated in serial cytosediments by the indigogenic method of Lojda. From quenched tissue samples taken from the same sites as those for cytology, a series of cryostat sections was prepared and stained by hematoxylin and eosin or azure A, or subjected to the reaction for acid beta-galactosidase. RESULTS: In 17 of 33 patients with cervical cancer, the same type of cancer was also found in smears of the endocervix and endometrium. In six patients the type of cancer was different. Of 44 patients with endometrial cancer, 16 had an endocervical malignancy of the same type. In seven cases the type of cancer was different. The reaction for acid beta-galactosidase helped in the differentiation between squamous (negative reaction in cancer cells) and cylindrocellular (positive reaction) cancer in cytologic preparations. CONCLUSION: Before treatment, it is necessary to determine if there is involvement of the endocervix in endometrial cancer and of the endometrium in cervical cancer. Routine cytologic examination supplemented by the reaction for acid beta-galactosidase proved to be useful for this purpose.     

False positive diagnosis in conventional and liquid-based cervical specimens

OBJECTIVE: To examine conventional and liquid-based cervical smears falsely diagnosed as malignant at our institution and to investigate, through cytologic-histologic correlation, factors influencing false positive diagnoses. STUDY DESIGN: Cervical cytologic diagnoses of malignancy from May 1, 1995, to April 30, 2001, were retrieved through a computer search. A retrospective review of hospital records and pathology reports was performed. Cases identified as false positives were reviewed and correlated with histologic follow-up specimens. RESULTS: A group of 68 patients with malignancy reported on cervical smears and with histologic follow-up was identified. Conventional smears numbered 32 (47%); the remaining 36 (53%) were liquid-based samples. Of the total, 7 false positive cases (10.3%) were identified in 4 conventional and 3 liquid-based preparations. Cytologic diagnosis in these cases was squamous cell carcinoma in 5 and adenocarcinoma in 2. On histologic follow-up, all 7 patients were ultimately found to have high grade squamous intraepithelial lesions (HSILs) without invasion. Review of the original slides confirmed most, or all, of the following features in all cases: major cellular pleomorphism, extensive cytoplasmic keratinization, intense nuclear pyknosis, background necrosis and severe atrophy. CONCLUSION: There was no significant difference in rates of false positive diagnoses between conventional (12.5%) and liquid-based (8.3%) samples. The chief reason for overdiagnosis in this series was the capacity of HSIL to exfoliate cells mimicking invasive malignancy, particularly when keratinized and especially in an atrophic milieu. The other cause of false positivity was superimposition of inflammation and atypical reparative change on a background of HSIL, which then suggested invasion.     

Atypical glandular cells of undetermined significance favor endometrial origin. Criteria for separating low grade endometrial adenocarcinoma from benign endometrial lesions

OBJECTIVE: To evaluate cytologic criteria for separating atypical glandular cells of undetermined significance favor endometrial origin (AGUS-EM), on Papanicolaou-stained (Pap) smears into favor benign and favor malignant categories. STUDY DESIGN: All patients who had a Pap smear diagnosis of AGUS-EM, not further qualified, followed by tissue follow-up were identified from the surgical pathology and cytopathology files from January 1992 through December 1996. The Pap smears were scored blindly for the presence or absence of 40 cytologic criteria, and univariate analysis was performed to determine which criteria were most indicative of malignancy by tissue follow-up. RESULTS: The presence of an atrophic smear, nuclear size greater than twice that of an intermediate cell nucleus and absence of clusters with irregular borders were highly indicative of adenocarcinoma, although other criteria were also helpful in identifying malignancy. CONCLUSION: There are no combinations of cytologic criteria that definitely separate AGUS-EM cases into those with benign or malignant findings on follow-up. However, some isolated criteria were useful in the differential diagnosis in a [table: see text] significant number of cases.     

Fractal dimension in aspiration cytology smears of breast and cervical lesions

OBJECTIVE: To standardize the automated measurement of fractal dimension on cytologic smears and compare the fractal dimension of benign and malignant breast cells and cervical lesions on cytologic material to evaluate its role in the discrimination of benign from malignant cells. STUDY DESIGN: We randomly selected fine needle aspiration cytology smears of 42 cases of infiltrating duct carcinoma and 38 cases of fibroadenoma of the breast. Similarly, 16 cervical carcinoma and 20 normal cervical smears were selected for study. Ten cells were selected randomly from each case. Box counting of fractal dimension of malignant and benign cells was achieved with an image cytometer (Leica, Cambridge, England) using Quantimet 600 software (Leica). Then a well-spaced grid with multiple small boxes of a particular pixel length was superimposed on the cell. The dimension of the box was selected as 4, 8 and 16 pixels. With the help of a logical "AND" operation, we counted the number of boxes touching the peripheral margin of the cell nuclei. For each cell, the log-log graph of 1 per box size was plotted against the number of boxes touching the peripheral rim of the cell. The slope of each graph was identified using the least-squares method of regression analysis. RESULTS: The mean fractal dimension of malignant cells was 0.8536 +/- 0.1120 as compared to 0.8403 +/- 0.1115 in benign cell groups. The Mann-Whitney U test showed a significant difference in fractal dimension in these 2 groups (P = .05). The mean fractal dimension of malignant cells from the cervix was 0.8656 +/- 0.1499 as compared to 0.8315 +/- 0.1312 in benign cells. The Mann-Whitney U test showed a significant difference in fractal dimension in these 2 groups (P < .02). CONCLUSION: Fractal dimension may be a helpful adjunctive technique to discriminate between benign and malignant cells.     

Cytologic findings in primary malignant carcinoid tumor of the cervix. Including immunohistochemistry and electron microscopy performed on cervical smears

The cytologic findings in a primary malignant carcinoid tumor of the cervix are presented. In addition to the presence in the smears of cells suggestive of squamous carcinoma and adenocarcinoma, which led to an initial diagnosis of adenosquamous carcinoma, there were multinucleated giant cells with prominent, reddish nucleoli, finely granular chromatin and grayish-blue to eosinophilic cytoplasm, as well as smaller pleomorphic cells, against a tumor-diathesis type of background. Immunocytochemistry performed on the cervical smears showed the presence of serotonin, and ultrastructural analysis revealed abundant intracytoplasmic, membrane-bound granules in malignant cells, thus confirming the diagnosis of a carcinoid tumor.     

Cytologic features of metastatic papillary thyroid carcinoma in cervical lymph nodes

OBJECTIVE: To elucidate the cytologic characteristics of metastatic papillary thyroid carcinoma (PTC) in cervical lymph nodes and the differences in cervical lymph nodes from those of stage I (intrathyroidal) PTC. STUDY DESIGN: Forty-seven cases of papillary thyroid carcinoma with cervical lymph node metastasis (group A) and 38 cases of intrathyroidal papillary carcinoma (group B) were included in this study. Preoperative fine needle aspiration cytology (FNAC) examination was performed on enlarged cervical lymph nodes (47 cases, group A) and enlarged thyroid nodules (13 cases, group A, and 38 cases, group B). All the cases were surgically excised and pathologically verified. The cytologic smears were reviewed and analyzed. RESULTS: The cytologic characteristics of metastatic PTC in cervical lymph nodes displayed a higher frequency of foamy macrophages (51.1% vs. 26.3%) and a lower frequency of distinct cell borders (38.3% vs. 71.1%) than those of stage I PTC. Metastatic PTC in cervical lymph nodes also had a higher frequency of cystic degeneration (44.7% vs. 5.3%) than intrathyroidal lesions. In 1 of the 47 cases with lymph node metastasis, the aspirate contained macrophages but no tumor cells. CONCLUSION: FNAC was useful in the diagnosis of metastatic PTC in cervical lymph nodes. However, because cystic degeneration appeared frequently, FNAC combined with thyroid ultrasonography to find the primary lesion is necessary in this situation.     

Cytodiagnosis of endometrial malignant mixed mesodermal tumor

The accuracy of endometrial aspiration smears obtained with the Isaacs cell sampler in the diagnosis of malignant mixed mesodermal tumors (MMMT) was compared to the results obtained with routine cervical and vaginal smears in five cases of MMMT found in a series of 220 endometrial aspirations. Cervical and vaginal smears previously taken on these patients were positive for adenocarcinoma or MMMT in two cases and suspicious for adenocarcinoma in the remaining three cases. Endometrial aspirates were positive for MMMT in three cases and positive for adenocarcinoma or MMMT in two cases. The endometrial aspiration smears contained a variety of cells: malignant glandular, squamous, spindly stromal, undifferentiated, osteoid and tumor giant cells; chondrocytes and free psammoma bodies were also observed. These cases indicated that endometrial aspiration can accurately detect the heterologous cellular elements found in MMMT and is an effective technique in its diagnosis.     

Cervicovaginal cytology in uterine adenocarcinoma and adenosquamous carcinoma. Comparison of cytologic and histologic findings

To investigate the diagnostic accuracy and to characterize the findings in false-negative cases, the results of cervicovaginal cytology in 56 adenocarcinomas and 25 adenosquamous carcinomas (42 cervical, 36 endometrial, 2 metastatic and 1 arising synchronously from both cervix and endometrium) were reviewed, including review of the actual slides in 56 cases. Overall, 80% of the initial cytologic diagnoses resulted in diagnostic curettage (i.e., cytology was effectively positive); 84% of the postreview diagnosis were effectively positive. Nine cytology slides showed no malignant cells; eight of these negative smears showed repair, five were atrophic, two showed a high estrogen effect and one had enlarged atypical bare nuclei. These false-negative diagnoses were associated with an endometrial primary site (P less than .01), endometrioid histology (P less than .005), low-grade or intermediate-grade histology (P less than .005), small size of tumor (P less than .05) and absence of cervical involvement (P less than .005) in those cases in which a hysterectomy was performed. False-negative diagnoses were not associated with an absence of endocervical cells or with scanty cellularity. Of 39 cervical and 28 endometrial carcinomas with a positive cytologic diagnosis (initially or after review of the available slides), cytology correctly identified the primary site in 18% and 54% of the cases, respectively. Cytology incorrectly classified the anatomic site of four cervical and three endometrial carcinomas and considered one case arising in both the endometrium and cervix to be endometrial. Routine cervicovaginal cytology does have a role in screening for uterine glandular carcinoma; to maximize its diagnostic sensitivity, we suggest using a recommendation for curettage in the report of positive cases so that all of the varied cytologic diagnoses associated with glandular carcinomas will receive a uniform clinical response. In those cases with preserved cancer cells, a correlation can be made with the histologic type of the carcinoma, rather than with the anatomic site.     

Ethnic patterns of cytologic abnormalities in cervical smears in suriname, a high-risk area for cervical cancer

OBJECTIVE: To determine the prevalence of cytologic abnormalities in cervical smears from women attending the first organized screening program in Suriname and to compare the prevalences in 4 Surinamese ethnicities with different cervical carcinoma incidences. STUDY DESIGN: Cervical scrapes were taken from women with 4 different ethnicities: Maroons, Amerindians, Javanese and Hindustani. Papanicolaou staining and cytologic screening were performed on 807 cervical smears. RESULTS Cervical cytologic abnormalities were seen in 13.4%, of which 8.1% (62 of 764) had atypical changes, 2.6% (20 of 764) had mild and 2.6% (20 of 764) had moderate and severe dysplasia/carcinoma in situ (CIS). The cytologic abnormalities varied between the ethnicities: 42.1% (83 of 197) in the Maroons and 2.3% (4 of 176), 5.0% (9 of 183) and 3.0% (6 of 208) in the Javanese, Amerindians, and Hindustani, respectively. CONCLUSION: The high prevalence of moderate and severe dysplasia/CIS in all ethnicities correlates with the high cervical carcinoma incidence in Suriname. A significantly higher prevalence of mild abnormalities in the Maroons was observed; it did not reflect the relatively low cervical cancer incidence in this ethnicity. However, this can be explained by the possibility that these women have a different sexual lifestyle, leading to a higher prevalence of     

Detection of Chlamydia trachomatis in Papanicolaou-stained cervical smears by an indirect immunoperoxidase method

A two-step (indirect) immunoperoxidase method directed against Chlamydia trachomatis was developed. The method was then used to evaluate the specificity of cytologic changes suggestive of C. trachomatis in Papanicolaou smears of cervical specimens from women who were culture-negative for the organism. Positive immunoperoxidase staining was detected in 9 of 21 cases (43%) tested. Technical problems, especially background staining, precluded interpretation in the remainder of the cases. Cervical cytology, as demonstrated by immunoperoxidase staining, may, in some instances, be more sensitive than the culture. However, because the etiology of cytologic changes not specifically identified by immunoperoxidase staining may be due to other organisms or factors, immunoperoxidase procedures, as described, should not replace culture for confirmation of cytologic findings suggestive of C. trachomatis.     

Histiocytes and the detection of endometrial adenocarcinoma

Histiocytes have long been recognized as part of the milieu of endometrial carcinoma in gynecologic smears. In an effort to determine whether a quantitative assessment of histiocytes, especially in the absence of endometrial cells, could increase the effectiveness of the cervicovaginal smear for diagnosis of endometrial carcinoma, smears obtained prior to a tissue diagnosis of endometrial adenocarcinoma were evaluated from 44 postmenopausal women. Smears from 97 age-matched patients in the same clinic were also evaluated and used as a control group for the endometrial carcinoma patients. All smears were evaluated for the presence of histiocytes and for the presence of benign or malignant endometrial cells, with the histiocytes quantitated as minimal (less than 5 per high-power field [HPF]), moderate (5 to 10/HPF) or heavy (greater than 10/HPF). Sensitivity and specificity were calculated to assess the role of histiocytes in the presence and in the absence of endometrial cells using cytologic findings. Our data indicate that the presence of moderate or heavy numbers of histiocytes on cervicovaginal smears of postmenopausal women increased the cytologic sensitivity from 61% to 82% when considered a marker of disease along with endometrial cells. These results suggest that attention to the presence of histiocytes on cervicovaginal smears may increase the utility of cytology for the diagnosis of endometrial lesions and may be a useful guideline for the cancer-related gynecologic examination.     

Giant cystic metaplastic carcinoma of the breast: a case report with diagnosis by fine needle aspiration

BACKGROUND: Breast cysts are mainly benign and are reported in association with fibrocystic disease and phyllodes tumor. Rarely have cystic changes been reported to occur in malignant tumors. They are usually small but large in rare cases. Giant breast cysts are very rare, and only a few cases have been reported. CASE: A 37-year-old woman presented with a rapidly growing breast mass. Mammography showed a huge, well-circumscribed cystic mass (17 x 16 x 16 cm) suggestive of a benign lesion. Cytologic examination revealed a highly cellular tumor composed of malignant cells of various sizes and shapes in a necrotic background. The smears were diagnosed as positive for malignancy and suggested metaplastic carcinoma. Mastectomy was performed, and histologic study confirmed the cytologic diagnosis. CONCLUSION: This is the first reported case of a breast cyst of this size. Clinically the cyst was confused with a benign lesion. The fine needle aspiration aided the diagnosis and planning of treatment.     

Microglandular hyperplasia of the uterine cervix. Cytologic diagnosis in cervical smears

OBJECTIVE: To identify cytomorphologic features specific to microglandular hyperplasia (MGH) in cervical cytologic smears. STUDY DESIGN: Twenty-four cervical smears from 24 patients obtained before the histologic diagnosis of MGH made on colposcopically directed biopsies during a period of two years (1995-1997) were evaluated. RESULTS: Of cases with MGH, 13/24 (54%) showed the presence of bidimensional or tridimensional cellular clusters made up of cubic or cylindrical glandular cells with vacuolated cytoplasm; cells with dense cytoplasm, basaloid in appearance, corresponding to immature squamous metaplasia; and subcylindrical reserve cells with small, round nuclei and scant cytoplasm. Clusters showed microlumina or fenestrated spaces, preserved polarity and absence of nuclear peripheral dispersion. In the control group these cellular clusters were found in 6/100 (6%). Statistical analysis (chi 2) showed a strong, highly significant association (P < 0.001) of the cytologic parameters selected and the histologic diagnosis of MGH. CONCLUSION: Until now, no specific cytologic parameters were described for MGH. This study underscored the value of cytomorphologic parameters described for typical cellular clusters showing microlumina or fenestrated spaces with shared party walls and an admixture of glandular cells, and immature squamous metaplastic and subcylindrical reserve cells in the cytologic diagnosis of MGH.     

Cribriform-morular variant of papillary thyroid carcinoma. Report of a case showing morules with peculiar nuclear clearing

BACKGROUND: There have been only 4 reported cases of cribriform-morular variant of papillary thyroid carcinoma (CMVPTC) with cytologic findings from fine needle aspiration. In these reports, the cytologic findings do not fully reflect the histologic characteristics of this entity. We report a case of CMVPTC in which a cribriform pattern without colloid and epithelial morules with peculiar nuclear clearing (PNC) were present in smears, thus fulfilling the criteria for a cytologic diagnosis of CMVPTC. Protein truncation tests for APC molecule abnormality indicated the presence of germline mutation in the patient's APC gene. CASE: A 30-year-old woman had multiple thyroid tumors. Aspiration cytology revealed a large number of round to spindle-shaped atypical-cells showing sheet-like, cribriform, follicular, whorl-like and solid, 3-dimensional arrangements. The cribriform and follicular arrangements did not contain colloid in the lumen. The powdery chromatin pattern characteristic of papillary carcinoma was not observed, but there were scattered intranuclear cytoplasmic pseudoinclusions and grooved nuclei. The nuclei of the atypical cells presenting in the whorl formations showed enlargement, thickened nuclear membranes and entirely clear contents, consistent with PNC. Hyalinelike necrotic cells were also observed in the cell clusters or in the background. Histologic and immunohistochemical findings were typical of CMVPTC. CONCLUSION: The cribriform pattern without colloid, fascicular or whorl formation of spindle cells, and morules with PNC are identifiable on cytologic smears and are sufficiently distinctive to allow a cytologic diagnosis of CMVPTC.     

False-negative results in cervical cytologic studies

The appropriate interval between cervical cytologic screening studies is a matter of considerable controversy, with a major consideration being the problem of false-negative results. To determine the rate of false-negative cervical cytologic results in our laboratory and to determine how these failures occur, tissue-proven cases of carcinoma in situ, invasive squamous-cell carcinoma, endocervical adenocarcinoma and lymphoid malignancy involving the cervix with negative Papanicolaou smears obtained within one year prior to the tissue diagnosis were reviewed. Over the four-year period from 1980 through 1983, 339 patients had tissue-proven cervical malignancies. Of these, 66 had false-negative Papanicolaou smears, representing a 20% overall false-negative rate. These false-negative smears were rescreened. For all types of cervical malignancy, the majority of errors were due to sampling. No malignancy was missed disproportionately by either cytotechnologists or cytopathologists. We plan to utilize these data for quality control purposes and for continued review of future performance.