Electron microscopic specimen preparation from low concentration of cell suspension using cytospin technique

Electron microscopic examinations are sometimes limited due to the small number of cells available for analysis. The purpose of this study was to determine the limit of cell concentration for a successful transmission electron microscopic preparation. Various concentrations of monocyte cell suspension were fixed in glutaraldehyde and osmium tetroxide according to the standard methods. Cell preparations were made on silane-coated glass slides in a cytospin centrifuge. The attached cells to the glass slides were dehydrated, and embedded in epoxy resin by routine electron microscopic technique. By this method, cell suspensions containing as low as 2x10(3) cells could show approximately 5 to 10 cells in each hole of the 150-mesh grids which was designated as the lowest limit for the successful preparation with detectable cells for evaluation. The fine structure of cells was clearly evident and the preparations were uniformly free from artifacts, similar or superior to those of cell pellet preparations. This method is useful whenever dealing with the samples containing a low number of cells, particularly those of clinical samples.

Cellular features of endometrial hyperplasia and well differentiated adenocarcinoma using the Endocyte sampler

BACKGROUND

Because cellular atypia is often limited in endometrial hyperplasia and well-differentiated endometrial adenocarcinoma (WHO Grade 1 adenocarcinoma), diagnostic criteria for endometrial cytology have not been fully established. New diagnostic criteria based on the composition and architecture of tissue fragments (cytoarchitecture) in the smears were used in the present study. Cytologic features are of less importance because the distinction between endometrial hyperplasia and Grade 1 adenocarcinoma relies more on architectural features than cellular changes. Cell clumps of various size are usually collected abundantly with cytologic material using a disposable scraping device and it was noticed that those cell clumps reflected the histologic architecture. The purpose of the current study was to determine the form of the cytoarchitecture that reflects the histologic structure and to examine the cellular features in endometrial hyperplasia and Grade 1 adenocarcinoma.

METHODS

The frequency of each type of cell clump (tube or sheet-shaped pattern, dilated or branched pattern, irregular protrusion, and papillotubular pattern) were obtained from 49 cases of normal proliferative endometrium (NPE) (patient age range, 28-51 yrs; average age, 39.9 yrs), 63 cases of endometrial hyperplasia without atypia (EH) (patient age range, 35-65 yrs; average age, 47.7 yrs), 13 cases of endometrial hyperplasia with atypia (AEH) (patient age range 47-65 yrs; average age, 53.8 yrs), and 49 cases of Grade 1 adenocarcinoma (patient age range, 42-73 yrs; average age, 58.9 yrs).

RESULTS

Certain characteristics of the cytoarchitecture were observed. In the NPE, cell clumps with a tube or sheet-shaped pattern were found in 97.5% of cases. In the EH, cell clumps with a dilated or branched pattern were found in 34.9% of cases. In the Grade 1 adenocarcinoma, cell clumps with irregular protrusions were found in 61.8% cases, whereas a papillotubular pattern was present in 29.7% of cases.

CONCLUSIONS

The results of the current study revealed that cytoarchitectural criteria appear to be more useful for the cytologic assessment of endometrial lesions, especially for the diagnosis of endometrial hyperplasia and Grade 1 adenocarcinoma.

Role of computerized morphometric analysis in diagnosis of effusion specimens

The present study was undertaken to compare morphometric analysis of cells in 100 effusion samples, with unaided cytological diagnosis. All the cases in the form of Leishman's stained smears were subjected to computerized-interactive morphometry (CIM) by usage of Image analysis software. On routine cytological examination, 44 cases were benign, 26 were malignant, and 30 cases were placed in "atypical" category. On morphometry, values for mean nuclear area (MNA) and mean cytoplasmic area (MCA) in benign cases were found to be 58.39 +/- 12.22 microm(2) and 185.70 +/- 43.69 microm(2), while for malignant cases were 120.12 +/- 16.28 microm(2) and 274.65 +/- 61.01 microm(2), respectively (P < 0.001, P < 0.001, highly significant). Significant differences were also noted among benign, atypical, and malignant cases for MNA (P < 0.001). The differences between atypical and malignant cases for N/C (nuclear/cytoplasmic) ratio were also found to be statistically significant (P < 0.001). Finally, 46 cases were found to be benign, 39 malignant, and 15 in the category of atypical cases. CIM helps in better and quicker sorting for malignant cells. MNA and N/C ratio are the most significant parameters in differentiating various cells in effusions. MCA constitutes as another useful parameter. Salient features of CIM, including their applications in the light of current study, are discussed.

Utility of millipore filter and cell block in thyroid needle aspirates: Which method is superior?

The main goal of thyroid fine-needle aspiration (FNA) is to distinguish nodules that require surgery from those that do not, thereby decreasing the number of diagnostic thyroidectomies. Several cytologic preparations are used to reach a definitive diagnosis, including smears using conventional stains, such as Diff-Quik (DQ) and Papanicolaou (Pap), millipore filters (MF), and cell blocks (CB). This study is undertaken to study the efficacy and adequacy to reach a definitive diagnosis of two cytologic preparations, MF and CB, in thyroid aspirates. All thyroid needle aspirates performed at Emory University Hospitals from January 2003 to April 2005 that had both MF and CB preparations for microscopic evaluation were studied. Conventional stains (DQ and Pap) were prepared. An initial aliquot of the specimen was divided for MF, and the remaining specimen submitted for CB preparation. All MF and CB slides were reviewed blindly. Adequacy criteria were assessed as 6-8 groups of follicular cells, with each containing 10 or more cells. Patient demographics, cytologic diagnoses, and follow-up information were retrieved. A total of 218 cases met our criteria; 21 of these cases were excluded due to lack of available diagnostic slides. Thus, a total of 197 cases were studied. Approximately two-third of the cases (57.9%) were diagnosed on DQ- and Pap-stained smears only, in which both CB and MF were inadequate. About 4.6% of the cases were diagnostic on both CB and MF; 36.0% on MF only, and 1.5% on CB preparation only. In more than half the cases (57.9%), diagnosis of thyroid FNA was rendered only on conventional stained smears. MF smears appeared to be superior for diagnostic yield (40.6%) than CB (6.1%), which is dependent on specimen cellularity. Therefore, MF rather than CB should be added to conventional stained smears (DQ and Pap) to supplement the diagnostic yield, especially in specimens of low cellularity.

Micromanipulation of single cells from tissue imprints is an alternative to laser-assisted microdissection

The characterization and analysis of single cells by molecular biological methods such as the polymerase chain reaction (PCR) is of increasing interest in biomedical research. Different techniques have been developed to obtain single cells from solid tissue. Currently, the most frequently used technique is laser-assisted microdissection (LAM). However, LAM of tissues cannot exclude contamination of the targeted cells by underlying cell fragments. Moreover, this technique can only be performed if a laser microscope is available. Thus, we developed a method to obtain single cells of fresh solid tissue by the simple technique of tissue imprints. After immunostaining of the imprints, single cells were transferred to a reaction tube using a 27-gauge needle guided by a mechanical micromanipulator. Consequently, we used these cells in a single cell PCR.

Detection of HTLV-1 gene on cytologic smear slides

In this chapter we describe a method for the detection of human T-cell leukemia virus type 1 (HTLV-1) genes in cytologic smears by polymerase chain reaction (PCR). First, already-stained and covered slides should be immersed in xylene for removal of cover slips. After passage through a descending ethanol series, slides are ready for DNA extraction. If the neoplastic cells on slides are mixed with nonneoplastic lymphocytes, cells of interest are isolated by microdissection. Two easy methods to dissect the samples using hydrophobic and hydrophilic mounting media are detailed. Second, microdissected cells are collected in microtubes and digested with proteinase K. The cells that did not undergo the microdissection are digested and dissolve in the proteinase K solution on the slides. Last, the template DNA is extracted from the solution and provided to PCR. We use two sets of primers for detection of HTLV-1 genes, and the products of amplification by PCR that correspond to the pX and tax regions are expected to be 127 and 159 base pairs long, respectively. Although this method does not provide proof of the monoclonal integration of HTLV-1 genes, it can be applied when adult T-cell leukemia/lymphoma is suspected cytologically but fresh samples for Southern blotting are unavailable.

Flow cytometric analysis of effusions in dogs and cats with the automated haematologyanalyser ADVIA 120

Samples were aspirated from 12 thoracic effusions, 10 abdominal effusions and four pericardial effusions in 17 dogs and nine cats. They were analysed cytometrically with the ADVIA 120 flow cytometer and the results were compared with the results of cytological examinations of May-Grünwald-Giemsa-stained smears. The conventional cytology revealed a purulent or pyogranulomatous inflammation in 12 of the animals, lymphoma in six, malignant histiocytosis in two, and an unspecified carcinoma in two; two animals had a chylous effusion, two had a modified transudate, and one dog had an idiopathic pericardial haemorrhage. The flow cytometric analysis was based on cellular volume, peroxidase staining intensity and the determination of nuclear lobularity, and made it possible to identify predominant cell lineages and cell debris, which were shown in characteristic cytograms. Inflammatory effusions, monocytic proliferation and lymphoma were easily detected, but carcinoma cells and mesothelial cells were classified as 'mononuclear blasts'.

Resolving ASCUS without recourse to HPV testing: Manual reprocessing of residual automated liquid-based cytology (ALBC) material using manual liquid-based cytology (MLBC)

We show that residual cell material from ThinPrep PapTest (Cytyc Corporation, Boxborough, MA) atypical squamous-cells of undetermined significance (ASCUS) cases may be manually reprocessed to triage women into actionable diagnostic categories (HSIL, LSIL, and Negative). Material remaining from each of 358 ThinPrep ASCUS cases was manually reprocessed as two slides, labeled "A" and "B." Interobserver agreement between case contributors (CCs) and three sequential reviewers (SRs) was analyzed with 186 cases (Study 1), and diagnostic reproducibility between SRs was examined with an additional 172 cases (Study 2). In Study 1, CCs classified 33% of cases as LSIL or greater, SRs classified 60% as LSIL or greater, and there was 58% diagnostic agreement between CCs and SRs. No "Negative" case assignment by one group afforded an "HSIL" assignment by the complementary group. In Study 2, there was 95% agreement between SRs A slide and B slide diagnoses with 54% of A slides and 55% of B slides classified as LISL or greater. Again, no "Negative" case assignment to one slide afforded an "HSIL" assignment to the complementary slide. Overall, 12.6% of the 358 cases showed HSIL, and all HSILs by one observer group were ASCUS or greater by the complementary observer group. Using manual reprocessing beyond the 21-day specimen outdate for HPV testing by the Hybrid Capture II High Risk HPV test (HR-HCII; Digene Corporation, Beltsville, MD), many ThinPrep ASCUS cases were reclassified as LSIL or HSIL. The 12.6% HSIL proportion of this study approximated the 11.5% CIN 2 or greater proportion of the ALTS ASCUS arm. Similar to ALTS, manual liquid-based cytology (MLBC) would have referred nearly 60% of women to colposcopy for a definitive diagnosis of HSIL or LSIL without resorting to HPV testing. These data demonstrate that many cases of automated liquid-based cytology (ALBC)-diagnosed ASCUS represent unrecognized SIL, which is present in the ALBC specimen vial at the time the ASCUS diagnosis is rendered.

Cell and tissue autofluorescence research and diagnostic applications

Cells contain molecules, which become fluorescent when excited by UV/Vis radiation of suitable wavelength. This fluorescence emission, arising from endogenous fluorophores, is an intrinsic property of cells and is called auto-fluorescence to be distinguished from fluorescent signals obtained by adding exogenous markers. The majority of cell auto-fluorescence originates from mitochondria and lysosomes. Together with aromatic amino acids and lipo-pigments, the most important endogenous fluorophores are pyridinic (NADPH) and flavin coenzymes. In tissues, the extracellular matrix often contributes to the auto-fluorescence emission more than the cellular component, because collagen and elastin have, among the endogenous fluorophores, a relatively high quantum yield. Changes occurring in the cell and tissue state during physiological and/or pathological processes result in modifications of the amount and distribution of endogenous fluorophores and chemical-physical properties of their microenvironment. Therefore, analytical techniques based on auto-fluorescence monitoring can be utilized in order to obtain information about morphological and physiological state of cells and tissues. Moreover, auto-fluorescence analysis can be performed in real time because it does not require any treatment of fixing or staining of the specimens. In the past few years spectroscopic and imaging techniques have been developed for many different applications both in basic research and diagnostics.

Cost efficiency analysis of modern cytocentrifugation methods versus liquid based (Cytyc Thinprep) processing of urinary samples

BACKGROUND/AIMS

Liquid based cytology (LBC) was developed as a replacement for cytocentrifugation in the treatment of cell suspensions. Because accurate data comparing the quality and total cost of modern cytocentrifugation methods versus LBC in non-gynaecological samples are not available, this study was designed to investigate these issues.

METHODS

The study comprised 224 urine samples treated with the Thermo Shandon Cytospin 4 using reusable TPX chambers, disposable Cytofunnels for samples up to 0.5 ml, and disposable Megafunnels for samples up to 6 ml. Each method was compared with the Cytyc Thinprep processing of a paired sample. Quality was assessed by scoring cellularity, fixation, red blood cells, leucocytes, abnormalities of urothelial cells, and suitability for molecular studies. Wage costs, investment, and consumables allowed a "total cost" to be calculated on the basis of 200 specimens/month. Total cost and quality combined were used to calculate an index of total quality (ITQ).

RESULTS

Cytocentrifugation with disposable chambers resulted in a global quality superior to that of Cytyc Thinprep LBC. Preparation and screening times were 2.25 and 1.33-2 times greater when using LBC compared with cytocentrifugation. The total cost each month reached 1960.23 $ to 2833.43 $ for cytocentrifugation methods and 5464.95 $ for Cytyc Thinprep LBC (92.8-178.8% increased cost). ITQ of cytocentrifugation with disposable chambers surpassed that of Cytyc Thinprep LBC (37.25/32.08 and 9.98, respectively).

CONCLUSION

Cytyc Thinprep LBC and cytocentrifugation are both appropriate methods for cytology based molecular studies, but cytocentrifugation remains the quality standard for current treatment of urinary samples because of its lower cost.

Liquid-based cytology as a tool for the performance of uCyt+ and Urovysion Multicolour-FISH in the detection of urothelial carcinoma

The aim of the study was to assess the value of liquid-based urinary cytology as a tool to perform uCyt+ and Multicolour-FISH in patients under follow-up after urothelial cancer. Therefore, standard cytology was compared to liquid-based cytology with the addition of the uCyt+ test, which traces the three monoclonal antibodies M344, LDQ10 and 19A211 in exfoliated urothelial cells; and Multicolour-FISH (including centromere-specific probes for chromosomes 3, 7, 17 and a locus-specific probe for 9p21/p16) performed on thin-layer specimens. UCyt+ showed an overall sensitivity of 86.2% and cytology of 45.0%. Overall sensitivity of both the tests combined was 90%. Sensitivity of Multicolour-FISH was 96.4%. All conventional cytology diagnoses were confirmed by liquid-based cytology. Liquid-based cytology is a valid tool for the performance of adjunctive analyses, such as uCyt+ and Multicolour-FISH, on residual cellular material.

Ocular surface impression cytology

Impression cytology, either using cellulose acetate strips or the Biopore membrane device, is a simple, noninvasive technique that aids in the diagnosis of several disorders of the ocular surface. These disorders include ocular surface squamous neoplasia, dry eye syndrome, limbal stem-cell deficiency, specific viral infections, vitamin A deficiency, allergic disorders, conjunctival melanosis, and malignant melanoma. Another advantage is the preservation of limbal stem cells, which occur in the basal layer of the limbal epithelium and are responsible for renewal of the corneal epithelium. The Biopore membrane device is particularly user friendly, with little expertise required and adequate specimens obtained in a very high percentage of cases. The most common applications in diagnostic ocular pathology are:(i) primary diagnosis and follow-up of ocular surface squamous neoplasia, including after therapy with topical mitomycin C. The sensitivity is high (78-87%); and (ii) dry eye syndrome where squamous metaplasia and/ or hyperkeratosis are noted. Certain limitations of the technique for diagnosis of squamous neoplasia include the fact that dysplasias are often keratinizing and may yield very few or even no dysplastic cells with impression cytology. Secondly, no definite cytologic criteria reliably distinguish invasive SCC of ocular surface from in situ disease. Other applications include the rapid specific diagnosis of ocular surface infections with herpes simplex, adeno-, and varicella zoster viruses. Impression cytology samples may also be used to obtain mRNA, cells for phenotyping by flow cytometry, and proteins for Western blotting for research studies.

Automated counting of white blood cells in synovial fluid

OBJECTIVES

To evaluate the performance of automated leucocyte (white blood cell; WBC) counting by comparison with manual counting.

METHODS

The number of WBC was determined in heparinized synovial fluid samples by the use of (i) a standard urine cytometer (Kova) and a microscope (reference method) and (ii) a haematology analyser (Sysmex XE-2100; WBC/BASO and DIFF channels). Imprecision within and between days was determined by replicate analysis of a low (level A; WBC approximately 0.560 x 10(9)/l) and a high (level B; WBC approximately 1.081 x 10(9)/l) dedicated synovial fluid control (Quantimetrix).

RESULTS

The WBC count of the DIFF channel was highly correlated with the WBC count of the microscopic reference method (r = 0.99; WBC analyser = 0.870 x WBC reference method + 0.413). In contrast, no agreement existed between WBC counts generated by the WBC/BASO channel of the analyser and the reference method (r = 0.52; WBC analyser = 0.008 x WBC reference method + 0.079). Within-day imprecision (4-7%) and between-day imprecision (10%) of the haematology analyser were smaller than the within-day imprecision (12%) and the between-day imprecision (20-22%) of the manual reference method. For manual counting, inter-observer coefficients of variation were 35.9% (control level A) and 21.0% (control level B).

CONCLUSIONS

The WBC count in synovial fluid can be reliably determined using the DIFF channel of the Sysmex XE-2100. Automated counting of WBC in synovial fluid offers more precise and faster results than manual counting.

Manual and automated AgNOR count in differentiating reactive mesothelial from metastatic malignant cells in serous effusions

OBJECTIVE

To distinguish reactive mesothelial cells from malignant cells in serous effusions using manual and automated methods of enumeration of argyrophilic nucleolar organizer regions (AgNORs).

STUDY DESIGN

In this prospective study, 38 samples of benign (19 cases) and malignant (19 cases) serous effusions were included. AgNOR stain was used in each case along with routine Papanicolaou stain. The smears were examined under an oil immersion objective, and AgNOR dots were counted by direct observation independently by 2 observers. Automated AgNOR counting and morphometry were performed with a Quantimet 600 image cytometer (Leica, Cambridge, England). At least 100 cells were counted in each case. The number of AgNOR dots in individual cells, AgNOR area, nuclear area, AgNOR vs. nuclear area and nuclear perimeter were measured. Data on benign and malignant cells were compared.

RESULTS

The AgNOR dots were discrete and smaller in benign effusion cases as compared to coarse and aggregated in malignant effusion cases. In benign reactive effusion cases the mean number of AgNOR dots per nucleus was 2.33 +/- 0.71 and 2.83 +/- 1.15 by the manual and automated method, respectively, whereas that for malignant effusion cases was 7.48 +/- 2.51 and 8.09 +/- 1.69 by the manual and automated method, respectively. Mean total AgNOR areas in benign and malignant groups were 4.77 +/- 2.66 microns 2 and 38.22 +/- 13.71 microns 2, respectively. Mean nuclear area, nuclear perimeter and ratio of AgNORs vs. nuclear area were 48.72 +/- 19.30 microns 2, 24.68 +/- 10.25 microns and .098 in benign effusion cases as compared to 174.25 +/- 82.36 microns 2, 69.03 +/- 27.23 microns and 0.22 in malignant effusion samples. All these values were significantly higher (P < .001, Student's t test) in malignant cells as compared to benign reactive cells.

CONCLUSION

AgNOR dot enumeration, AgNOR area and ratio of AgNORs to nuclear area are valuable adjuncts to cytomorphology in differentiating reactive mesothelial cells from malignant cells in serous effusions. Automated AgNOR counting is rapid and less cumbersome.

Role of cytology in the diagnosis of Barrett's esophagus and associated neoplasia

We studied 327 consecutive paired esophageal biopsies and brushing specimens obtained during the same endoscopic session to evaluate the role of cytology for the diagnosis of Barrett's esophagus (BE) and/or surveillance for associated dysplasia. A diagnosis of BE was based on the cytologic presence of goblet cells. Cases were reviewed and categorized into: 1) benign esophageal lesions (125 cases), with 48 cases of Candida (32 cases diagnosed by both techniques and 16 diagnosed only by cytology), 3 cases of herpes simplex with only 1 case diagnosed by cytology, and 74 cases of inflammation and/or repair; 2) benign BE (141 cases), with 74 cases (52%) diagnosed by both techniques, 11 cases by cytology only (8%), and 56 cases (40%) by histology only; 3) low-grade dysplasia (LGD, 30 cases), with 5 cases (17%) diagnosed with both specimens, one case (3%) by cytology only, and 24 cases (80%) by histology only; 4) high-grade dysplasia (HGD, 10 cases), with 8 cases (80%) diagnosed with both specimens, 1 case (10%) by cytology, and 1 case (10%) by histology; and 5) carcinomas (23 cases), with 20 cases (87%) diagnosed with both specimens, 2 cases (9%) by cytology only, and 1 case (4%) by histology only. Our results support the high degree of diagnostic accuracy of cytology for the diagnosis of Barrett's-associated HGD and/or carcinoma, and moderate sensitivity for BE.

Reclassification of "atypical" diagnoses in endoscopic retrograde cholangiopancreaticography-guided biliary brushings

OBJECTIVE

To evaluate the usefulness of reclassifying "atypical" diagnoses in reporting biliary cytology using strict morphologic criteria.

STUDY DESIGN

Cytologic specimens from 139 patients (direct, alcohol-fixed smears or cytocentrifuge preparations) were evaluated. Diagnoses were benign (70), atypical (36) and malignant (33). Using strict criteria--major (nuclear contour, chromatin pattern) and minor (polarity, cell types, nuclear size, nuclear grooves, nucleoli, mitosis, nuclear/cytoplasmic [N/C] ratio)--atypical cases were reevaluated and reclassified. Follow-up (F/U) was available on all cases.

RESULTS

Atypical cases, (36) were reclassified as malignant (26), atypical favor benign (2)/reactive (3) and atypical, not otherwise specified (NOS) (5). Cases reclassified as malignant showed irregular nuclear contours, chromatin irregularities and rare mitosis. Nuclear enlargement, nucleoli and cellularity varied widely in all groups. N/C ratio was increased in most reclassified malignant cases. All 26 malignant reclassifications correlated with F/U of malignancy. Benign and reactive cases (5) were negative for malignancy on F/U (4), and in 1 case a metastatic carcinoma involving the biliary tree was found. In the 5 atypical (NOS) cases, F/U showed malignancy (3) and pancreatitis (2). Cytocentrifuge preparations made in our laboratory were of superior quality when compared to other methods of cell preparation.

CONCLUSION

Irregularities in nuclear membrane and abnormal chromatin pattern were the most consistently useful features correlating with malignancy. The sensitivity and specificity of biliary brush cytology can be enhanced by using strict cytomorphologic criteria and proper collection and fixation, all of which decrease atypical diagnoses.

Brush cytology of colorectal malignancies

OBJECTIVE

To evaluate the specificity and sensitivity of brush cytology and biopsy in colorectal malignancies.

STUDY DESIGN

The study was performed over 3 years, 1998-2000. Seventy-six patients with any colorectal lesion on colonoscopy were selected, and in all of them brush cytology and biopsy were done at the same time. The cytologic smears and biopsies were reviewed separately. The cytologic smears were categorized as negative, suspicious, suggestive or positive for malignancy. The results of cytology and biopsy were compared based on sensitivity and specificity. The gold standard for positive cases was the tissue specimen after surgery; negative cases were followed for at least 1 year. Cases with 1 year of disease-free survival were considered negative.

RESULTS

Among 76 cases, 4 were excluded because of unsatisfactory cytologic smears. Of the remaining 72 cases, 31 were male and 41 female. The age range was 19-80 years. Cytology showed 23 positive and 49 negative cases (1 false positive and 3 false negative). Biopsy showed 24 positive and 48 negative cases (no false positives and 1 false negative). There were 47 negative cases, followed for at least 1 year, and after that we considered them definitively negative for malignancy. Sensitivity of cytology and biopsy was 88% and 96%; specificity was 98% and 100%, respectively. Combined use of brush cytology and biopsy had the highest sensitivity, 100%.

CONCLUSION

Brush cytology of the colon is a safe, fast and reliable method for the diagnosis of colorectal cancer. We recommend performing it in conjunction with biopsy. It is also reasonable to perform a repeat biopsy in patients with negative biopsy and positive cytology for a definitive diagnosis.

Fetal cells in cervical mucus in the first trimester of pregnancy

OBJECTIVES

The aim of this study was to first evaluate the presence of fetal cells in cervical mucus samples collected in the first trimester of pregnancy and then to compare different laboratory methods for the detection of these cells.

METHODS

Mucus samples were collected by using a cytobrush before termination of pregnancy (TOP) from 143 pregnant women between 7 and 12 weeks of gestation. None of the women had undergone an invasive diagnostic procedure prior to cervical mucus sampling. Samples of placental tissue were collected from each patient at TOP. Slides from each sample were first observed under an inverted microscope to detect possible sperm contamination. In the first part of our experiments, 40 mucus samples were treated with a mucolytic solution containing N-acetylcysteine (AC) and were analysed by a polymerase chain reaction (PCR) assay. The second series, consisting of 71 mucus samples, was treated with a mucolytic solution containing dithiothreitol (DTT): all 71 samples were analysed by a PCR-based assay, and an aliquot for fluorescent in situ hybridisation (FISH) analysis was also obtained from 48 out of 71 samples. In the third part of our experiments, performed on 32 mucus samples, mucus trapped on the cytobrush was directly spread on two slides for FISH analysis without any mucolytic treatment. All placental tissue samples obtained at termination were analysed by FISH for fetal sexing.

RESULTS

Overall, the use of PCR-based or FISH analyses on 143 mucus samples resulted in correct sex prediction in 92/143 (64.3%) samples [20/66 (30.3%) cases from known male pregnancies and 72/77 (93.5%) cases from known female pregnancies]. In the AC group, Y-derived sequences were found in 7/23 samples (30.4%) from known male pregnancies and in 1/17 cases from known female pregnancies, with an overall correct sex prediction in 23/40 cases (57.5%). In the DTT group, Y-derived sequences could be amplified in 10/30 samples (33.3%) from known male pregnancies and in 4/41 cases from known female pregnancies, with an overall correct sex prediction in 47/71 cases (66.2%). In the DTT samples analysed by FISH, nuclei bearing XY signals were detected in 5/26 (19.2%) cases from known male pregnancies and in none from female pregnancies, the rate of correct sex prediction being 56.2% (27/48). On untreated mucus samples analysed by FISH, nuclei with XY signals were documented in 3/13 (23%) samples from male conceptuses and in none from known female pregnancies, with an overall correct sex prediction in 22/32 cases (68.7%).

CONCLUSION

Fetal cells were not detected in a constant and reliable fashion in cervical mucus samples collected in the first trimester of pregnancy. The detection rate was poorly influenced by the use of different laboratory methods. This sampling technique cannot be regarded as a promising tool towards minimally invasive prenatal diagnosis.

Cytologic features of high-grade squamous intraepithelial lesions involving endocervical glands on ThinPrep cytology

Usage of liquid-based cytology has resulted in better cellular preservation with enhancement of nuclear features. The purpose of this retrospective 2-yr study (January 1999 through December 2000) was to evaluate the cellular features of endocervical gland involvement by a high-grade squamous intraepithelial lesion (HSIL) vs. endocervical adenocarcinoma in situ (AIS) on cell samples processed by the ThinPrep method as compared to conventional smears. Of the 97 cases of CIN III diagnosed on cytology, 52 (54%) showed surface endocervical gland involvement by CIN III and form the basis of this study. There were also six cases of endocervical AIS diagnosed on histology with prior cytology. The architectural features of HSIL involving endocervical glands and AIS were similar to those previously reported on conventional smears. A consistent finding of HSIL involving endocervical glands was the loss of central cell polarity and piling within cell groups, a finding not present in AIS. Central cell polarity was maintained in cellular groupings of AIS. In addition to the cellular feature present on conventional smears, micronucleoli were clearly visualized in cells of HSIL involving endocervical glands and prominent nucleoli were present in AIS. Apoptosis and mitoses were clearly visualized in both entities. Endocervical gland involvement by HSIL has characteristic cell patterns and features on liquid-based/thin-layer cytology that permit their distinction from AIS.