Routine Cytological Examination Research Articles

Usefulness of Various Diagnostic Techniques during Fiberoptic Bronchoscopy for Endoscopically Visible Lung Cancer: Should Cytologic Examinations Be Performed Routinely?

Background: The question of which combination of procedures gives the best diagnostic yield following fiberoptic bronchoscopy is controversial. Objectives: To evaluate the value of various diagnostic techniques following fiberoptic bronchoscopy in the diagnosis of endoscopically visible lung cancer. Methods: The study included 98 patients found to have endobronchially visible tumor during routine daily bronchoscopy. Endobronchial lesions were classified as mass, submucosal lesion and infiltration. Washings, brushings and forceps biopsies were obtained in all subjects. Transbronchial needle aspirations were performed in 67 of 76 cases with mass or submucosal lesions. Results: Bronchoscopy was diagnostic for cancer in 88 (89.8%) of the 98 patients. Forceps biopsy specimens gave positive result in 82.7% of cases, transbronchial needle aspirates in 68.6%, brushings in 68.4%, and washings in 31.6%. Combination of forceps biopsy and brushing cytology yielded a positive result for lung cancer in 87 patients. The addition of brushings increased the diagnostic yield of bronchoscopy from 82.7% to 88.8% (p < 0.05). Collection of washing specimens in addition to forceps biopsy did not increase the yield of forceps biopsy. Transbronchial needle aspiration gave an additional yield of 1%. Conclusions: Routine cytological examination of bronchial washings does not increase the yield of forceps biopsy specimens. Transbronchial needle aspiration may give an additional positive yield to forceps biopsy. We conclude that a combination of forceps biopsy and brushing is the best strategy in the diagnosis of bronchoscopically visible lung cancer.

Immunostaining for Met/HGF receptor may be useful to identify malignancies in thyroid lesions classified suspicious at fine-needle aspiration biopsy.

The receptor for hepatocyte growth factor (Met) is not expressed in the normal thyroid but it is overexpressed in most thyroid carcinomas. We evaluated whether Met immunostaining of cytological smears from fine-needle aspiration biopsy (FNAB) may be useful for the preoperative diagnosis of thyroid cancer. Notably, routine cytological examination often fails to distinguish well-differentiated follicular carcinomas and a proportion of papillary carcinomas (low-grade papillary carcinomas and papillary carcinomas follicular variant [FVPTC]) from benign lesions: all these lesions are usually classified as suspicious. We examined 80 thyroid lesions diagnosed as suspicious at cytology that had subsequently undergone surgery. The histologic diagnosis had been: papillary carcinomas (n = 14), FVPTC (n = 11), follicular carcinomas (n = 25), atypical follicular adenomas (n = 5), follicular adenomas (n = 20), and nodular goiters (n = 5). We also studied typical papillary carcinomas (n = 30) and nodular goiters (n = 10), all correctly diagnosed at cytology. In lesions classified suspicious at routine cytology, Met immunostaining was positive in 12 of 14 (85.7%) papillary carcinomas, 8 of 11 (72.7%) FVPTC, 7 of 25 (28%) follicular carcinomas, and 5 of 5 atypical adenomas. In contrast, none of the 25 lesions cytologically suspicious but benign at histology were positive. These data suggest that Met immunostaining of suspicious cytological smears are useful for identifying malignant lesions, especially those with a papillary histotype.

Detection of telomerase reverse transcriptase mRNA in biopsy specimens and bile for diagnosis of biliary tract cancers.

Human telomerase reverse transcriptase (hTERT), which codes for the catalytic subunit of telomerase, is essential for telomerase activity. Recent studies revealed that levels of hTERT mRNA as well as telomerase activity are high in neoplasm. The purpose of this study was to correlate the expression of hTERT mRNA with telomerase activity in biopsy specimens and bile from biliary tract cancers and to evaluate the potential diagnostic value of hTERT mRNA analysis for biliary malignancy. We analyzed hTERT mRNA and telomerase activity in biopsy specimens and exfoliated bile cells from patients with cholangiocarcinoma, gallbladder carcinoma and bile duct stones. hTERT was detected by either nested reverse transcriptase-polymerase chain reaction (PCR) or real-time PCR. Telomerase activity was examined by a fluorescence-based telomeric repeat amplification protocol assay. Six of 10 malignant biopsy specimens had detectable hTERT and 7 of 10 had telomerase activity. All cases with hTERT expression had telomerase activity. In bile, 7 of 10 malignant patients had detectable hTERT and 3 of 10 had telomerase activity. Importantly, there were no false positive results in tissue specimens or bile examined in 6 non-cancerous cases. In conclusion, the detection of hTERT mRNA in biopsy specimens and bile cells, in combination with routine histologic and cytologic examination may improve the diagnosis of biliary tract cancers.

Treatment of leptomeningeal metastases evaluated by interphase cytogenetics.

Although cytologic examination of CSF is the primary method for the evaluation of response to therapy for leptomeningeal metastases (LMMs), the procedure's sensitivity decreases throughout the course of protracted therapy. We studied whether this response could be monitored more accurately through the detection of numerical chromosomal aberrations by interphase cytogenetics, using fluorescence in situ hybridization (FISH). Seven patients treated for LMMs and with a known numerical aberration for chromosome 1 in their pretreatment CSF were included in this study. Up to 16 consecutive CSF samples were analyzed by means of the fluorescence in situ hybridization (FISH) technique for cells with aberrant chromosome 1 content. The results of routine cytology and FISH analyses were compared and were correlated with each patient's neurologic status. Routine cytology detected malignancies in only 24 of the 76 samples, all of which were classified as chromosomally abnormal by FISH (except for two samples that could not be evaluated). Moreover, FISH demonstrated aneusomic cells in 32 additional samples, which could therefore be classified as malignant. The FISH results correlated better with patient neurologic status in that more malignant cells were detected in the CSF of neurologically deteriorating patients. Using FISH in addition to performing routine cytologic examination of CSF led to a more accurate evaluation of response to treatment in patients treated for LMMs.

Cytologic Detection of Cervical and Endometrial Carcinoma with Other Genital Tract Involvement

To investigate the possibility of a correct cytologic diagnosis of cervical and endometrial carcinoma with other genital organ involvement. 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. 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. 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.

Morphologic Features of Bone Marrow Metastasis in Neuroblastoma: A Review

In practice, the diagnosis of bone marrow (BM) involvement by neuroblastoma (NB) is made by routine cytologic and histologic examination. The purpose of this review is to provide guidelines for processing and to describe the histologic and cytologic features of BM involvement in NB. It is recommended that two sets of adequate samples of bilateral BM aspirates and biopsies from the posterior iliac crests be obtained. Routinely prepared smears of BM aspirates, Wright-Giemsa stained, and sections of formalin-fixed, decalcified BM biopsy specimens are adequate for routine histologic examination and immunoperoxidase stains. Five cytologic patterns of involvement in pretreatment aspirates are described in this review: 1. Isolated undifferentiated small round tumor cells; 2. Diffuse sheets of small round tumor cells; 3. Aggregates of small round tumor cells with nuclear molding; 4. Tumor cells with neuropil in the background, with or without rosettes; and 5. Differentiating neuroblasts and ganglion cells. Four histologic patterns were found in pretreatment biopsies: 1. Undifferentiated neuroblasts without neuropil; 2. Neuroblasts with minimal neuropil; 3. Neuroblasts with moderate to abundant neuropil; and 4. Differentiating neuroblasts and ganglion cells. Posttreatment aspirates and biopsies showed three patterns of involvement: 1. Remnant undifferentiated or poorly differentiated neuroblasts; 2. Maturation with ganglion cells and/or Schwannian differentiation; and 3. Fibrosis with or without isolated neuroblasts and/or Schwann cells. Immunohistochemical stains for neural markers should be used to confirm the neuroblastic nature of the tumor cells.

Detection of telomerase activity in exfoliated cancer cells obtained from bile.

Telomerase is detected by the telomeric repeat amplification protocol (TRAP) assay in more than 85% of primary cancers. In the present study, we determined telomerase activity using exfoliated bile cells obtained from biliary tract neoplasia specimens. The aim of this study was to provide additional information regarding minimally invasive approaches to the detection of biliary tract cancer in combination with routine cytologic examination. We analyzed for telomerase activity bile juice from patients with gallbladder carcinoma, cholangiocarcinoma, cholecystitis and cholangitis. Semiquantitative determination of telomerase activity was performed using both a fluorescence-based TRAP assay on cell extracts and at the cellular level by an in situ TRAP assay. The fluorescence-based TRAP assay detected bile telomerase activity in samples from 4 of 10 patients with biliary tract cancer. In contrast, the in situ TRAP assay detected telomerase positive cells in samples from 6 of 10 patients with biliary tract cancer. However, only one of these samples showed class V cytology. A combination of semiquantitative analysis and an in situ TRAP assay to detect telomerase positive cells may improve the diagnosis of biliary tract cancers with the combination of routine cytologic examination.

Pulmonary cryptococcoma with CD4 lymphocytopenia and meningitis in an HIV-negative patient

Cryptococcus neoformans is a ubiquitous yeast which is usually found in pigeon and chicken excreta. With the increased use of steroid and immunosuppressive agents and the increasing incidence of acquired immunodeficiency syndrome (AIDS), the incidence of cryptococcal disease seems to be increasing (1). Clinically, the most commonly recognized form of cryptococcal disease is chronic meningitis (2). In some post mortem studies, C. neofoYmans has presented in the lung and the central nervous system with equal frequency (3,4). The present case report describes a case of pulmonary cryptococcoma with CD4 lymphocytopenia and meningitis, but without HIV infection. Routine cytological examination of sputum and transcutaneous fine needle biopsy provide a judicious assessment to approach this disease. The clinicopathologic features, radiological findings and treatment are discussed.

Impalpable breast cysts: utility of cytologic examination of fluid obtained with radiologically guided aspiration.

To evaluate the utility of cytologic analysis of fluid obtained from impalpable breast cysts by means of radiologically guided aspiration. The authors retrospectively reviewed the reports of cytologic examinations of fluid obtained with sonographically or mammographically guided aspiration of 660 impalpable breast cysts in 583 women during 3 1/2 years. No malignant cells (541 cysts) or insufficient cellular material (86 cysts) was seen with cytologic examination of 95% of the aspirates. Atypical cells were seen with cytologic examination of fluid from 33 (5%) lesions. None of these 33 lesions were found to represent malignancy at the time of surgical excision (n = 9) or during clinical follow-up (n = 24). Routine cytologic examination is unnecessary if the fluid obtained with radiologically guided aspiration from impalpable breast cysts is not bloody.

Tropical liver abscess.

Forty-one consecutive cases of liver abscesses seen at the National University Hospital, Singapore from 1988 to 1994 were reviewed. Twenty-seven cases (65%) were pyogenic, six (15%) amoebic, two (5%) tuberculous...

Interphase fluorescence in situ hybridization improves the detection of malignant cells in effusions from breast cancer patients.

In diagnostic evaluation of effusions, difficulties are encountered when atypical reactive mesothelial cells have to be differentiated from malignant cells. We tested the impact of fluorescence in situ hybridization (FISH) to identify metastatic cells in breast cancer effusions by detection of numerical chromosomal changes. Pleural and ascitic fluid samples (n=57) from 41 breast cancer patients were concomitantly evaluated by routine cytology and FISH, using centromere-specific probes representing chromosomes 7, 11, 12, 17 and 18. After setting stringent cut-off levels deduced from non-malignant control effusions (n=9), the rates of cells with true aneuploidy were determined in each effusion sample from breast cancer patients. The occurrence of aneuploid cells, as detected by FISH and indicative of malignancy, was correlated with the cytological findings. Routine cytology revealed malignancy in 60% of effusions. Using FISH, aneuploid cell populations could be observed in 94% of cytologically positive and in 48% of cytologically negative effusions, thus reverting diagnosis to malignancy. To confirm malignancy in cases with a low frequency of aneuploid cells, two-colour FISH was additionally performed and indeed showed heterogeneous chromosomal aneuploidy within single nuclei. We conclude that FISH is a valuable tool in the diagnosis of malignancy and may serve as an adjunct to routine cytological examination, as demonstrated here for breast cancer effusions.

Detection of bladder tumor by urine cytology in cases of prostatic hypertrophy.

Routine urine cytology has been performed for 809 male patients presenting with symptoms due to prostatic hypertrophy. In 6.42% of the cases, bladder tumor was revealed incidentally diagnosed by urine cytology. Cystoscopy and bladder biopsies were performed to confirm malignancy. The age of these patients ranged from 48-84 years (mean 65.2) and they complained mainly of irritative bladder symptoms. It is therefore strongly indicated that all patients with prostatic disease should have routine cytological examination of urine sediments.

An immunocytochemical study of ras and myc oncoproteins and EGFr expression in pleural effusion smears

Pleural effusion smears from 112 patients with either benign or malignant lung disease were investigated for the expression of EGFr and the oncogene proteins myc p64 and ras p21. The streptavidin-biotin peroxidase technique was used. In the studied malignant group of effusions both EGFr and ras have greater sensitivity in the detection of a malignant process than does routine cytological examination though EGFr was less specific. The combination of positive cytology and 3 positive markers is highly specific for a malignant process (90%). Myc and ras had a 100% sensitivity in squamous cell carcinomas but an overall specificity of only 67.3% and 66.6% respectively. The differences in myc and ms positivity, between squamous cell and adenocarcinoma effusion smears were highly significant (p <0.005). All effusion smears associated with undifferentiated carcinomas were ras positive and 2 of them were myc and EGFr positive.

Screening for cervical intraepithelial neoplasia grade 2/3: Validity of cytologic study, cervicography, and human papillomavirus detection

OBJECTIVE: A commercial test for human papillomavirus detection (hybrid capture assay) was examined for its potential value to augment the sensitivity of cytologic study or cervicography for screening for cervical intraepithelial neoplasia grade 2/3. STUDY DESIGN: In a cohort of 967 women with a mean age of 37.1 years who underwent routine cytologic screening, cytologic examination, cervicography, and testing for high-risk human papillomavirus by the hybrid capture assay were compared for their ability to detect cervical intraepithelial neoplasia grade 2/3. Cervical punch biopsy specimens were taken in 20.5% (198/967) patients because they had an atypical or positive cervigram or abnormal cytologic results in the primary screening smears. The data were analyzed by two-tailed χ 2 and Fisher's exact test. RESULTS: Thirty-eight patients were diagnosed with cervical intraepithelial neoplasia grade 2/3 (prevalence 3.9%) by histologic study. Cytologic study identified 29%, cervicography 45%, and testing for high-risk human papillomavirus 50% of cervical intraepithelial neoplasia grade 2/3. When combined, detection of high-risk human papillomavirus or cervicography augmented sensitivity of cytologic study to 58% ( p = 0.01) with positive predictive values of 23% and 17%, respectively. Results of the different techniques should be interpreted in relationship to each other and not as absolute values because collection of specimens for cytologic study was done with cotton swabs, which may be suboptimal for screening but is general practice in Germany. CONCLUSIONS: Screening for cervical intraepithelial neoplasia grade 2/3 can significantly be improved by human papillomavirus testing with the hybrid capture assay. (AM J OBSTET GYNECOL 1996;174:1534-41.)

Contribution of immunocytochemistry in routine diagnostic cytology.

The authors report the experience of applying immunocytochemistry in routine cytological examination and its contribution for diagnosis during a period of 3 yr in Veterans General Hospital-Taipei, Taiwan. From August 1991 to July 1994, the cytology laboratory received 5,762 non-gynecologic specimens with urine excluded. Immunocytochemistry was performed selectively in problematic cases. A total of 215 stainings including 124 epithelial markers, 50 lymphoma/leukemia markers, 22 neuroglial and choroid plexus markers, seven mesenchymal markers, six melanoma markers, and six others was performed on 145 specimens consisting of 89 effusions, 28 fine-needle aspirations, 11 cerebrospinal fluids, and 17 other specimens. Effusions were by far the most frequent specimens for immunocytochemistry and the epithelial markers were the most frequently used antibodies. The immunocytochemical results were essential in 41 specimens (28%), confirmatory in 37 (26%), and non-contributory in 67 (46%). Essential and confirmatory results occurred in 49% of effusions (44/89), 71% of fine-needle aspirations (20/28), 55% of cerebrospinal fluids (6/11), and 47% of other specimens (8/17). It is concluded that immunocytochemistry is proved to be a good aid for the final diagnosis of daily cytologic practices in which the fine-needle aspiration specimens are benefitted best.

Bronchoscopic Diagnosis of Solitary Pulmonary Nodules and Lung Masses in the Absence of Endobronchial Abnormality

To evaluate the individual and additive diagnostic yield(s) of several bronchoscopic sampling techniques for the diagnosis of lung lesions with no corresponding airway abnormalities, consecutive patients with lung nodules or masses were prospectively evaluated between December 1989 and November 1994. A CT of the chest was done in all patients before flexible bronchoscopy (FB). Size, location, and character of the border of the lesion were determined. During FB, using biplane fluoroscopic guidance, the lesion was localized and following sampling techniques were done: brushing, transbronchial lung biopsy (TBLB), and Sofcor transbronchial needle aspiration (STBNA). Bronchial washings (BWs) were collected throughout the procedure. Problems associated with each sampling technique were noted. Forty-nine patients underwent 51 FB. A diagnosis was established by FB in 36 (73%). After a nondiagnostic FB, histologic diagnosis was established in 9 of 13 patients by other methods. A benign or malignant nature of lesion was established in other four patients by clinical follow-up. FB was diagnostic in 32 of 40 (80%) patients with primary lung cancer, in 3 of 6 (50%) patients with benign disease, and in 1 of 3 (33%) patients with metastatic disease to lung. All sampling procedures could be done in 33 of 51 (65%) FBs. Overall diagnostic yields were as follows: BW, 18 of 51 (35%); brush, 25 of 48 (52%); TBLB, 23 of 40 (57%); and STBNA, 19 of 37 (51%). In 12 of 51 (24%) FBs, only one sample was diagnostic. Lesions with sharp borders had a lower combined diagnostic yield, 13 of 24 (54%) compared to lesions with fuzzy borders, 20 of 24 (83%) (p=0.03). Yield of TBLB in lesions with fuzzy borders, 14 of 18 (78%), was higher than the yield for lesions with sharp borders, 6 of 19 (32%) (p=0.005). Size of the lesion in centimeters in patients with a positive FB (4.55+/- 2.35; mean +/-SD) was significantly larger than in patients with a nondiagnostic FB (3.14+/-1.31; mean+/-SD) (p=0.009, t test). Diagnostic yield was directly related to the size of the lesion. For lesions less than 2 cm, yield was 6 of 11 (54%) (p=0.19); for lesions less than 3 cm, yield was 12 of 21 (57%) (p=0.07); and for lesions greater than 3 cm, yield was 24 of 30 (80%). Yield from lesions located in the lower lobe basal segments or the apical segment of upper lobes was lower (11/19, 58%) than that from lesions in other parts of the lung (25/30, 83%) (p=0.05). FB was terminated prior to collecting all samples because of severe bleeding after brushing (n=3) or instability of the patient (n=4). None of the patients required intubation. There were no pneumothoraces. Diagnostic yield of FB depends on the location, size, character of the border of the lesion, and the ability to perform all sampling methods. Brushing, TBLB, and STBNA should be performed in all patients to give the best diagnostic yield. Routine cytologic examination of BW is unnecessary. Methods other than FB should be considered for lesions 2 cm or less in size, especially when they have a sharp border and/or are located in the basal segment of a lower lobe/apical segment of an upper lobe.

Immunhistochemische Untersuchungen zum Antikörpermuster (Tumormarker) am Larynx

Tumour markers are gaining in importance for the histological differentiation of the squamous cell tumours. They can be implemented in the differentiation of precancerous lesions from cancers. Until now, such immunohistochemical methods have been reported only for the larynx for differentiating precancerous transformation from the normal epithelium by means of antigen specificity; none of these methods, however, are suitable for cytological application. We investigated via the immunopap method a palette of antibodies including our own markers (B/A 2). The proliferation marker Ki 67 is found to be specific in various cells, especially in basal cells. Markers with broad spectrum such as CEA and EMA are of little importance for routine laryngeal diagnosis because of uncharacteristic diffuse reactions. EMA antibodies marked the cylindrical cells. S-100, Vimentin, Ulex, and Factor VIII reacted as non-squamous cell markers. S-100 marked, besides the peripheral nerves, also the small salivary glands of the larynx. Ulex showed mild reaction with all squamous cells. We recommend the epithelial markers B/A 2 and CK 13 for routine histological and cytological examination of the larynx. For detection of proliferation Ki 67 is the appropriate marker.

Cost-effectiveness of cervical cytologic examination during pregnancy.

We undertook a study to determine the cost-effectiveness of performing routine cervical cytologic examination during pregnancy. The costs generated by doing routine prenatal cervical cytologic examination were calculated based on chart review in a family practice setting. A consecutive sample of 523 patients giving birth during 1990 was used. Analysis was done on 423 of those patients with prenatal Papanicolaou smear results recorded. Cost savings from detection of curable disease and utility of the test in terms of well-years saved were calculated from published statistics using a single-step Markov process to model the population at risk. For patients of all ages using a discount rate of 5 percent, the cost generated by prenatal cervical cytologic examination was $146,400 per well-year of life saved. Age stratification showed cost per well-year to range from $321,600 for patients aged 15 to 19 years to $48,800 for those aged 35 to 39 years. Routine prenatal cervical cytologic examination is significantly less cost-effective than the most commonly done medical procedures. If medical funding is limited, elimination of this test should be considered for women with normal findings on cervical cytologic examinations within the previous 2 to 3 years.

Immunocytochemical Panel for the Identification of Malignant Cells in Serous Effusions

The cytologic diagnosis of malignancy in serous effusions can be challenging. An immunocytochemical (ICC) panel using commercially available antibodies (to carcinoembryonic antigen [CEA], epithelial membrane antigen [EMA], B72.3, Leu-M1, cytokeratin [CK], leukocyte common antigen [LCA], S-100 protein, and vimentin) was applied to cell blocks fixed in methyl Carnoy's solution that were from 55 consecutive pleural, peritoneal, and pericardial fluid specimens. The results were correlated with data from clinical records and routine cytologic studies. Final cytologic diagnoses included 26 of adenocarcinoma and 1 of mesothelioma. The remaining 28 cases were considered to be benign (reactive) proliferations. EMA, CEA, B72.3, and Leu-M1 were present in 96%, 77%, 58%, and 42% of adenocarcinomas, respectively. These determinants were absent in the mesothelioma and the reactive effusions, although anti-CEA yielded strong background staining of inflammatory cells. The CK markers identified malignant cells in 93% of cases, but consistently stained mesothelial cells as well. Antivimentin strongly labeled mesothelial cells in all cases, with weak to absent staining of malignant cells. In 3 of 26 carcinoma cases (12%), the ICC panel identified malignant cells that were not recognized initially on routine cytologic examination. In 1 of 26 cases (4%), the panel was falsely negative. Use of this approach can improve the diagnostic accuracy of cytologic examination of serous fluids. The ICC panel is especially helpful when atypical mesothelial proliferation is present, or in cases that are clinically suspect for malignancy, but cytologically negative because there are only a few malignant cells, or those that are cytologically bland.

Human papillomavirus infection in the cervix of pregnant females in Hong Kong

Routine cytological examination and HPV-DNA probing were performed on cervical cells obtained from 215 pregnant Chinese females. The procedure utilized the specific binding of a mixture of complementary [32P]-labelled RNA probes to membrane-bound target HPV DNA types 6, 11, 16, 18, 31, 33 and 35. Positive results for HPV-DNA were obtained in 11/215 (5%) of the cases. The cervical smears were routinely processed and in 3/215 (1.5%) cases a cytological diagnosis of wart virus infection was made. All three were included in the 11 probe-positive cases. Using similar molecular biological techniques, pregnant Western females have an incidence of HPV infection of the cervix which is up to five times that of the present series. This is an unexpected finding in view of the fact that the incidence of cervical cancer is higher in Chinese women than American women.