Analysis of pleural effusions using automated flow cytometry

Value of automatic DNA image cytometry for diagnosing lung cancer

The present study aimed to investigate the diagnostic value of automatic DNA image cytometry (DNA-ICM) for diagnosing lung cancer. A total of three different types of samples from 465 cases were included: Bronchoalveolar lavage fluid (BALF), 386 samples; pleural effusion cases, 70 samples; and fine-needle aspiration procedures, 9 samples. Two methods, liquid-based cytology (LBC) and automatic DNA-ICM, were used to assess the samples, and the pathological results of 120/465 cases were reviewed. The results of DNA-ICM were compared with those of LBC and pathology. There were 57 cases of lung cancer without aneuploidy and 49 cases without evidence of malignant tumor, but with the presence of heteroploid cells. The positive diagnostic rate for BALF samples using LBC was significantly higher compared with that for DNA-ICM (P<0.05). No statistically significant difference was observed in the positive diagnostic rate between DNA-ICM and LBC in pleural effusion samples. For DNA-ICM in BALF, pleural effusion and all samples, no statistically significant differences were identified between the positive diagnostic rates of lung squamous carcinoma and lung adenocarcinoma. The positive diagnostic rate of LBC combined with DNA-ICM was not significantly improved. In non-small cell lung cancer (NSCLC) cases, the difference in the maximum value of DNA (DNAmax) was positively correlated with tumor stage (P<0.05), but no significant correlations were observed among DNA max, tumor type and tumor location. In small-cell lung cancer (SCLC) cases, no significant correlations were observed among DNAmax, tumor staging or tumor location. The differences in the DNAmax values of squamous cell carcinoma, adenocarcinoma, SCLC and NSCLC were not statistically significant. In the present study, the area under the receiver operating characteristic curve for LBC (0.936) was significantly greater compared with that for DNA-ICM (0.766) (P<0.05). DNA-ICM has medium diagnostic value in lung cancer, and the DNAmax was positively correlated with tumor stage in NSCLC. DNA-ICM may serve as a supplement to LBC, but it is not recommended as a sole procedure for lung cancer screening.

Methods for simultaneous measurement of apoptosis and cell surface phenotype of epithelial cells in effusions by flow cytometry

We describe here a protocol for the detection of epithelial cells in effusions combined with quantification of apoptosis by flow cytometry (FCM). The procedure described consists of the following stages: culturing and induction of apoptosis by staurosporine in control ovarian carcinoma cell lines (SKOV-3 and OVCAR-8); preparation of effusion specimens and cell lines for staining; staining of cancer cells in effusions and cell lines for cell surface markers (Ber-EP4, EpCAM and CD45) and intracellular/nuclear markers of apoptosis (cleaved caspase-3 and caspase-8, and incorporated deoxyuridine triphosphates); and FCM analysis of stained cell lines and effusions. This protocol identifies a specific cell population in cytologically heterogeneous clinical specimens and applies two methods to measure different aspects of apoptosis in the cell population of interest. The cleaved caspase and deoxyuridine triphosphate incorporation FCM assays are run in parallel and require (including sample preparation, staining, instrument adjustment and data acquisition) 8 h. The culturing of cell lines requires 2-3 days and induction of apoptosis requires 16 h.

Flow cytometric immunophenotyping of cancer cells in effusion specimens: Diagnostic and research applications

Flow cytometry (FCM) immunophenotyping is frequently used as an ancillary technique for the diagnosis of hematological malignancies or for measurement of DNA content. In recent years, we applied FCM to the diagnosis of metastatic adenocarcinoma and malignant mesothelioma in effusions. We established a panel of antibodies that allows for rapid and effective differentiation between epithelial cells, mesothelial cells, and leukocytes. FCM was subsequently used for quantitative analysis of integrin subunits. Recently, we studied different parameters of the immune response, including HLA molecules and chemokine receptors, using this method. Our data suggest that FCM is an effective method for the characterization of cancer cells in clinical effusion specimens in both the diagnostic and research setting, and that this method is comparable to immunohistochemistry in terms of sensitivity and specificity, with the additional advantage of providing quantitative data. This review discusses previous work in this area and the future potential of this method in the characterization of tumor cells in serous effusions.

Flow cytometric immunphenotyping of epithelial cancer cells in effusions—Technical considerations and pitfalls

BACKGROUND

Data regarding the role of flow cytometry (FCM) in the characterization of malignant effusions are limited to date. In the present study, we optimized the conditions for FCM immunphenotyping of effusions using a four-color analysis and investigated aspects related to the advantages and limitations of this method in this setting.

METHODS

FCM analysis optimization for the study of epithelial cells was undertaken using five carcinoma cell lines, and subsequently applied to malignant pleural and peritoneal effusions using antibodies against epithelial and mesothelial markers (Ber-EP4 and EMA), CD138, and integrin subunits. FCM of frozen versus fresh specimens and the performance of FCM compared to immunhistochemistry were evaluated.

RESULTS

FCM optimization was achieved and applied to clinical specimens, with resulting detection of epithelial markers and adhesion molecules on cancer cells. Frozen clinical specimens and cell lines showed reduced CD138 expression compared to fresh specimens, with conservation of the remaining epitopes. FCM generally showed comparable performance to immunhistochemistry.

CONCLUSIONS

FCM is an effective method for characterization of cancer cells in clinical effusion specimens in both the diagnostic and research setting, and is comparable to immunhistochemistry in terms of sensitivity and specificity, with the additional advantage of providing quantitative data. The majority of epitopes are conserved in frozen cells, but a minority may be lost, suggesting that the thorough testing of each antibody in both conditions is mandatory.

Use of mesothelin as a marker for mesothelial cells in cytologic specimens

Immunocytochemistry is often employed for the distinction between mesothelial cells and adenocarcinoma. Mesothelin has recently been reported to be expressed in reactive mesothelial cells and epithelioid mesotheliomas. The objective of this study is to determine the utility of mesothelin as marker for mesothelial cells in cytologic preparations. Thirty cell blocks were retrieved from the archives and immunostained with monoclonal antibody directed against mesothelin and calretinin. Heat-induced epitope retrieval technique was employed, and the immunostaining was accomplished using an automated stainer. These tissue blocks were from 35 patients (17 females and 18 males) with a median age of 64 years. Nine were benign effusions, 11 mesotheliomas, and 18 metastatic adenocarcinomas. The presence of any immunoreactivity, irrespective of level of intensity or percentage of cells, was considered positive for mesothelin expression. Follow up included correlation with pathology materials obtained at surgery and review of medical records. Mesothelin staining was positive in 7/9 benign cases, 8/11 mesotheliomas, and 8/18 adenocarcinomas. The difference of mesothelin expression between mesothelial cells and adenocarcinoma was statistically significant. For calretinin, all cases, except 2 malignant mesotheliomas and 3 adenocarcinomas, showed positive staining with calretinin. As a marker for mesothelial cells, the sensitivity and specificity of mesothelin were 73% and 55%, respectively, and the sensitivity and specificity of calretinin were 95% and 86%, respectively. Therefore, mesothelin is not a sensitive or a specific marker for mesothelial cells in cytologic specimens when compared with calretinin.

Quantitative analysis of integrin expression in effusions using flow cytometric immunophenotyping

We have previously shown that flow cytometric (FCM) immunophenotyping is a useful adjunct to morphology, in the diagnosis of serous effusions. The objective of the present study was to evaluate the possible application of FCM to quantitative analysis of adhesion molecule expression in this clinical setting. Fresh frozen cells from 67 effusions underwent quantitative analysis of alphaV, alpha6, beta1, and beta3 integrin subunit expression, using FCM. Specimens were diagnosed as carcinoma (n = 48), reactive (n = 12), or malignant mesothelioma (MM; n = 7) using morphology and, in selected cases, immunocytochemistry prior to FCM analysis. Antibodies against established epithelial, lymphoid, and mesothelial cell epitopes (Ber-EP4, anti-epithelial membrane antigen; (EMA), anti-CD45, anti-CD14, and anti-CD15) completed the panel. Results (percentage of cells expressing the antigen) were analyzed for relationship with the morphologic diagnosis. Frequent expression of the alphaV, alpha6, and beta1 subunits was seen in all diagnostic groups, with significantly higher expression of the alpha6 subunit in MM (P = 0.029, Kruskal-Wallis H test). The beta3 integrin subunit was not detected in any of the specimens. Ber-EP4 and CD15 expression was significantly higher in carcinomas compared with reactive effusions and MM (P < 0.001 and P = 0.001, Kruskal-Wallis H test), and EMA expression was higher in carcinomas and MM, compared with reactive specimens (P < 0.001, Kruskal-Wallis H test). In conclusion, FCM is an efficient tool for quantitative analysis of adhesion molecules in effusions. The high alpha6 integrin subunit expression in MM suggests involvement of this receptor in tumor attachment to laminin. The frequent expression of the alphaV and beta1 subunits support attachment to fibronectin and vitronectin as the major ECM ligands in body cavities.

Detection of malignant epithelial cells in effusions using flow cytometric immunophenotyping: an analysis of 92 cases

We compared the efficiency of immunophenotyping using flow cytometry (FCM) and a combination of morphologic and immunocytochemical studies for detecting malignant cells in 92 effusions. Cytologic results were as follows: carcinoma cells, 43 specimens; benign, 42 specimens; suggestive of nonepithelial malignancy, 7 specimens. After immunocytochemical analysis, 5 benign specimens were reclassified as malignant and 4 malignant epithelial specimens as benign. With FCM, cells positive for Ber-EP4, B 72.3, AH6, and HB-TN were detected in 28 to 36 (64%-82%) of 44 carcinomas but only 2 to 12 (5%-29%) of 41 benign specimens. Significant association was seen for coexpression. Ber-EP4 and AH6 were the most sensitive; Ber-EP4 was the most specific. The presence of cells positive for 3 of 4 markers strongly suggested malignancy (34/44 carcinoma specimens [77%]; 3/41 reactive specimens [7%]). The presence of cells positive for all 4 markers was diagnostic of malignancy (17/44 malignant specimens [39%]; 0/41 reactive effusions [0%]). FCM and immunocytochemical resultsfor Ber-EP4 expression showed excellent association. FCM is a powerful tool for diagnosing difficult effusions and can quantify coexpression of various markers in fresh specimens. By using established cellular markers coupled with biological markers, FCM also has great promise for experimental purposes.

Use of a panel of markers in the differential diagnosis of adenocarcinoma and reactive mesothelial cells in fluid cytology

To evaluate the use of a panel of markers to differentiate adenocarcinoma and the reactive/inflammatory process in fluid cytology, we stained 29 formalin-fixed, paraffin-embedded cell blocks of effusion fluid from patients with metastatic adenocarcinoma and 24 cell blocks from patients with benign effusion with mucicarmine and antibodies to carcinoembryonic antigen (CEA), B72.3, and calretinin. Positive staining with CEA, B72.3, and mucicarmine was seen in 22 (76%), 20 (69%), and 18 (62%) adenocarcinoma cases, respectively. All except 1 adenocarcinoma was negative for calretinin. No benign cases were positive for B72.3 and mucicarmine. In 1 benign case, scattered epithelial cells demonstrated weak positivity for CEA. The majority of combinations were 100% specific for adenocarcinoma. The highest sensitivity (86%) for adenocarcinomas was achieved with the staining combination of negative for calretinin and positive for any adenocarcinoma marker (CEA, B72.3, or mucicarmine). The use of a panel of markers that recognize adenocarcinoma and mesothelial cells is useful in the differential diagnosis between metastatic adenocarcinoma and the reactive/inflammatory process. The profile of positive staining with at least one of the adenocarcinoma markers and negative calretinin staining is highly specific and sensitive for identifying adenocarcinoma in fluid cytology.

Detection of monocyte/macrophage cell populations in effusions: a comparative study using flow cytometric immunophenotyping and immunocytochemistry

The objective of the present study was to compare the efficiency of immunophenotyping using flow cytometry (FCM) and immunocytochemistry (ICC) in the detection of macrophages in serous effusions. Cytoblock sections from 90 effusions were stained for the monocyte/macrophage marker CD14, using ICC. Fresh-frozen samples of all cases were analyzed for CD14 expression, using FCM. Epithelial, lymphoid, and mesothelial cell populations were identified using antibodies against Ber-EP4, CD45, and N-cadherin, respectively. Results were compared with clinical parameters and morphological diagnosis. Thirty-nine specimens were cytologically diagnosed as malignant, containing tumor cells of nonhematologic origin, whereas 46 were interpreted as benign. Two additional specimens were diagnosed as indeterminate or suspicious for malignancy, and 3 specimens contained lymphoma cells. CD14-positive cells were detected in 85/90 (94%) of effusions using FCM, and in all 90 specimens using ICC. The percentage of CD14-positive cells was highly variable, but in some specimens was as high as 76% using FCM and 85% using ICC. A good association was observed between the two methods in the detection of CD14-positive cells (P < 0.001). The presence of macrophages in effusions showed an association with female gender, using both FCM (P = 0.002) and ICC (P = 0.011), but none with effusion site, patient age, clinical and cytological diagnosis, or presence of Ber-EP4-positive cells (P > 0.05). The presence of Ber-EP4-positive cells showed a strong association with the cytological diagnosis of malignancy (P < 0.001). In conclusion, macrophages are a significant cell population in effusions, of both benign and malignant etiology, due to both their size and their possible confusion with cancer cells. Both FCM and ICC aid in the recognition of these cells, and thus provide an effective tool for the identification of different cell populations in effusions.

Flow cytometry in the diagnosis of peritoneal carcinomatosis

OBJECTIVES

Peritoneal carcinomatosis is the second major cause of ascites. Because of its frequency and poor prognosis, it is important to establish an accurate diagnosis. The aim of this study was to analyze the use of a DNA index, detemined by flow cytometry in the differential diagnosis of ascites, and to compare it to the cytopathological examination.

METHODS

A prospective analysis was carried out on 67 patients (39 female, 28 male; mean age, 53+/-14 yr [range, 5-82]) with ascites of various etiologies. Peritoneal carcinomatosis was detected in 21 patients, whereas in 46 the ascites was of noncarcinomatosis origin.

RESULTS

The sensitivity of the cytopathological examination for the diagnosis of peritoneal carcinomatosis was 42.9%, and the specificity was 100%. The mean DNA index determined by flow cytometry was similar for peritoneal carcinomatosis and noncarcinomatosis patients, being 1.28 versus 1.01, respectively, in the preparations without control lymphocytes and 1.28 versus 1.04, respectively, when control lymphocytes were added. The sensitivity of DNA index cytometry was 57.1% and specificity, 93.5%. The combined use of the DNA index and cytopathological examination did not show an advantage over the use of any of the tests individually, although the DNA index was able to detect half of the cases of peritoneal carcinomatosis in which cytopathological examination was negative. Although the sensitivity was higher when the parameters were associated, the DNA index did not offer a statistically significant advantage over the use of cytopathological examination alone, which in turn had higher specificity.

CONCLUSION

The DNA index presented lower sensitivity for the diagnosis of peritoneal carcinomatosis when used alone, showing no advantage over conventional cytopathological examination. However, the DNA index was able to detect 50.0% of peritoneal carcinomatosis cases whose conventional cytopathological examinations were negative, and could be valuable in these situations.

Flow cytometric immunophenotyping of serous effusions and peritoneal washings: comparison with immunocytochemistry and morphological findings

AIM

To evaluate immunophenotyping by means of flow cytometry as a complementary method for the detection of malignant cells in serous effusions and peritoneal washings.

MATERIAL AND METHODS

Frozen samples of 49 fresh serous effusions and peritoneal washings were analysed by flow cytometry, using monoclonal antibodies against CD45, Ber-EP4, and N-cadherin. Results were compared with smear and cell block morphology, as well as immunocytochemistry on paraffin wax embedded cell blocks.

RESULTS

Seventeen specimens were cytologically diagnosed as malignant, whereas 25 were interpreted as benign. The remaining seven specimens were diagnosed as indeterminate or suspicious for malignancy. Ber-EP4 positive cells were detected in 16 of the 17 cytologically malignant effusions, as well as in five of seven suspicious cases and five of 25 specimens with benign cytology. In the latter group, three specimens showed atypical or malignant cell groups that were missed in routine morphological evaluation. In two additional samples, obtained from patients with benign and borderline ovarian tumours, Ber-EP4 positive cells showed benign or mildly atypical features, and were interpreted as exfoliated benign or borderline malignant epithelial cells of tubal origin, or as endosalpingiosis. All five Ber-EP4 positive indeterminate specimens showed atypical or malignant cells on re-evaluation, and were Ber-EP4 positive in four of five cases using immunohistochemistry in cell block sections. Large numbers of CD45 positive and relatively few N-cadherin positive cells were detected in most specimens with the use of flow cytometry, when compared with morphological evaluation.

CONCLUSIONS

Flow cytometry is a rapid and highly effective method for the evaluation of effusions and peritoneal washings. The detection of Ber-EP4 positive cells using flow cytometry is strongly indicative of the presence of carcinoma cells in effusions and peritoneal washings. Although false positives are relatively infrequent, all specimens should be carefully evaluated morphologically to prevent the diagnosis of benign epithelial clusters as malignant.

Calretinin staining pattern aids in the differentiation of mesothelioma from adenocarcinoma in serous effusions

BACKGROUND

The differentiation between malignant mesothelioma and adenocarcinoma based on morphology alone can be a diagnostic challenge. The majority of the available antibodies recognize molecules expressed by adenocarcinoma whereas to the authors' knowledge specific markers for mesothelial cells are lacking. Calretinin, a calcium-binding protein, has been reported to be a selective marker for mesothelioma and largely is absent from adenocarcinoma on histologic material. The results with cytologic preparations have been inconsistent.

METHODS

To evaluate the specificity of calretinin in differentiating mesothelioma from adenocarcinoma in cytologic preparations, 21 paraffin embedded cells blocks of serous effusions from 15 patients with metastatic adenocarcinoma and 16 cell blocks from 9 patients with malignant mesothelioma were stained with a monoclonal antibody against calretinin. The immunoreactivity was evaluated blindly by two observers. Positive staining was defined as nuclear and cytoplasmic staining with or without intense membranous decoration. The former resulted in a characteristic "fried egg" appearance.

RESULTS

Calretinin staining was positive in all but 2 cases of mesothelioma (14 of 16 cases; 87.5%). The latter contained predominantly spindle-shaped neoplastic mesothelial cells in the cell block preparations. All adenocarcinoma specimens were classified as negative for calretinin staining; 9 (42.9%) lacked any immunoreactivity and 12 (57.1%) showed weak, sparse, coarse, granular cytoplasmic staining without nuclear or membranous staining. Benign reactive mesothelial cells, when observed in association with adenocarcinoma, also showed the characteristic "fried egg" appearance. The difference in the staining pattern of calretinin between cells of mesothelial origin and adenocarcinoma cells was statistically significant.

CONCLUSIONS

Calretinin is a useful marker in differentiating mesothelioma of the epithelial type from adenocarcinoma in serous effusions. The "fried-egg" appearance or cytoplasmic and nuclear staining pattern is characteristic of cells of mesothelial origin.

Role of DNA flow cytometry and image cytometry on effusion fluid

The objective of the study was to assess the value of DNA flow cytometry (FCM) and image cytometry (ICM) as an adjunct to routine diagnostic cytology. In this prospective study, 100 consecutive effusion fluids were studied for routine cytology, DNA FCM, and in selected cases, ICM. One half of the centrifuged fluid sample was used for routine cytology and the remaining portion was used for DNA FCM. Nuclear area, nuclear diameter, nuclear perimeter, nuclear convex perimeter, nuclear roundess, and nuclear convex area were measured on at least 100 cells by ICM in cytologically malignant or DNA aneuploid cases along with control cases. Clinical follow-up was done in all cases. There were 22 cytologically malignant cases and 78 cytologically benign cases. Among the 22 cytologically malignant cases, there were 11 aneuploid and diploid cases each by DNA FCM. Out of 78 cytologically benign cases, six (7.7%) were aneuploid by DNA FCM. Smears of these cases showed predominantly reactive mesothelial cells, but the DNA histograms showed hypodiploid (one), hyperdiploid (three), tetraploid (one), and hypertetraploid (one) aneuploidy. Follow-up of these cases showed clinical or histologic features of malignancy except in one case of tetraploid aneuploidy, which did not show any features of malignancy and responded well to antitubercular therapy. Therefore, out of 27 malignant effusions, DNA FCM picked up 16 cases and routine cytology detected 22 cases. Sensitivity and specificity of DNA FCM were thus 59.25% and 98.63%, respectively. There was a statistically significant difference (Student's unpaired t-test, P < 0.05) between cytologically malignant cases and control benign cases in all the nuclear morphometric parameters except for nuclear roundness. There was, however, no statistically significant difference of nuclear morphometric parameters between cytologically benign vs. DNA aneuploid cases and control benign cases. DNA FCM is a useful adjunct for routine diagnostic cytology. Visual diagnostic cytology and morphometric digital microscopy miss some cases of malignancy which can be detected by DNA flow cytometry. Diagn. Cytopathol. 2000;22:81-85.

Role of DNA flow cytometry and image cytometry on effusion fluid

The objective of the study was to assess the value of DNA flow cytometry (FCM) and image cytometry (ICM) as an adjunct to routine diagnostic cytology. In this prospective study, 100 consecutive effusion fluids were studied for routine cytology, DNA FCM, and in selected cases, ICM. One half of the centrifuged fluid sample was used for routine cytology and the remaining portion was used for DNA FCM. Nuclear area, nuclear diameter, nuclear perimeter, nuclear convex perimeter, nuclear roundess, and nuclear convex area were measured on at least 100 cells by ICM in cytologically malignant or DNA aneuploid cases along with control cases. Clinical follow-up was done in all cases. There were 22 cytologically malignant cases and 78 cytologically benign cases. Among the 22 cytologically malignant cases, there were 11 aneuploid and diploid cases each by DNA FCM. Out of 78 cytologically benign cases, six (7.7%) were aneuploid by DNA FCM. Smears of these cases showed predominantly reactive mesothelial cells, but the DNA histograms showed hypodiploid (one), hyperdiploid (three), tetraploid (one), and hypertetraploid (one) aneuploidy. Follow-up of these cases showed clinical or histologic features of malignancy except in one case of tetraploid aneuploidy, which did not show any features of malignancy and responded well to antitubercular therapy. Therefore, out of 27 malignant effusions, DNA FCM picked up 16 cases and routine cytology detected 22 cases. Sensitivity and specificity of DNA FCM were thus 59.25% and 98.63%, respectively. There was a statistically significant difference (Student's unpaired t-test, P < 0.05) between cytologically malignant cases and control benign cases in all the nuclear morphometric parameters except for nuclear roundness. There was, however, no statistically significant difference of nuclear morphometric parameters between cytologically benign vs. DNA aneuploid cases and control benign cases. DNA FCM is a useful adjunct for routine diagnostic cytology. Visual diagnostic cytology and morphometric digital microscopy miss some cases of malignancy which can be detected by DNA flow cytometry. Diagn. Cytopathol. 2000;22:81-85.

Clinical value of DNA image cytometry in effusions with atypia

Malignant cells in serosal effusions provide essential information about the extent of malignant disease. The main aim of this study was to examine the additional diagnostic value of DNA image cytometry for cases with uncertainty in the cytological diagnosis. In addition, the feasibility of automated nuclei detection was investigated. Out of 457 cases, 33 samples in 32 patients were diagnosed with "atypia" (probably benign) and 21 as "suspicious for malignancy." DNA image cytometry was performed on these 54 cases and on an additional group of 14 cytologically malignant cases. The results show that automatic classification is useful for separation of control cells, i.e., lymphocytes and neutrophilic granulocytes from other mononuclear cells. In 21 cases an insufficient number of control cells were measured. Seventy-two percent of the cytologic malignant cases were aneuploid. In contrast, in none of the cases with "atypia" and in only 2 of the cases "suspicious for malignancy" was aneuploidy present (2 of the remaining 32, 6%). From the cases with follow-up, a malignancy in the pleural fluid was present in 2 out of 17 cases with "atypia" and in 5 out of 10 with a "suspicious for malignancy" cytologic diagnosis, respectively. In conclusion, the additional diagnostic value of DNA image cytometry in cases with a cytological diagnosis of "atypia" or "suspicious for malignancy" is limited. Diagn. Cytopathol. 1999;21:112-116.

Benign and malignant cells in effusions: diagnostic value of image DNA cytometry in comparison to cytological analysis

Identifying tumor cells in body cavity fluids reliably is a well-known diagnostic problem. Since cytometric quantitation of nuclear DNA content appears to be a promising new tool in the diagnosis and prognostic evaluation of many solid human tumors, we examined its validity in detecting malignant cells in cytologically positive effusions. For this purpose, image DNA cytometric measurements, including the evaluation of DNA-ploidy and the calculation of the DNA index (DI), were performed in 80 body cavity fluids. The results were correlated with cytology, clinical course and final histological diagnoses. We used aneuploidy, as shown by interactive image DNA cytometry, as a marker for the malignancy of cells that occur in body cavity fluids with a 100% specificity and 94.8% sensitivity. Cytological investigation showed a 92.3% specificity and 95.4% sensitivity. Combining both methods raised the specificity to 100% and the sensitivity to 98.5% and had a positive predictive value of 100% and a negative predictive value of 93.8%. The DNA-index (DI) was significantly higher in malignant effusions than in benign effusions: 1.5 +/- 0.74 (mean +/- SD) versus 1.11 +/- 0.26 (p < 0.05). Along with the difficult cytological evaluation of malignant cells in body cavity fluids, image DNA cytometry can be a helpful additional method for evaluating these cells. Combining the two techniques results in a highly specific and sensitive prediction of malignant cells. We, therefore, suggest using these methods for the reliable identification of tumor cells in effusions.

Applications of flow cytometric DNA analysis to diagnostic cytology

Flow cytometry is a rapid method for measuring DNA content. Its high sensitivity and specificity in detecting transitional cell carcinomas in bladder washings should make it a routinely applied adjunct to cytology once universal laboratory standards are firmly established. Diagnostic and prognostic information on solid tumors can be obtained at least as reliably on fine-needle aspirations as on surgically resected specimens. At the present time, the sensitivity of FCM in the evaluation of effusions, peritoneal washings, and CSF is relatively low, and although in some cases malignant cells in these specimens that are missed by conventional cytology are detected by FCM, the number of such cases is small. Investigation continues into the application of FCM to the screening of cervical specimens.

Comparison of nucleolar organiser regions and DNA flow cytometry in the evaluation of pleural effusion

BACKGROUND

In conventional cytological diagnosis of pleural effusions the assessment of morphological features plays an important part. However, false negative and false positive results may occur. In this study conventional cytology was compared with flow cytometric DNA analysis and the argyrophil staining technique for nucleolar organiser regions (AgNOR) to characterise benign and malignant effusions.

METHODS

Pleural effusions from 71 patients (38 with benign lung disease, 33 with proven adenocarcinoma of lung) were studied by conventional cytology, flow cytometric DNA analysis, and the AgNOR technique. Tumour cell ploidy was determined by flow cytometry. In an attempt to detect the cell proliferative state, flow cytometric S phase fraction and the AgNOR technique were used. The correlations among conventional cytology, flow cytometric DNA ploidy, S phase fraction analysis, and nucleolar organiser regions were investigated.

RESULTS

All the 38 benign pleural effusions were diploid. There were 17 (52%) aneuploid and 16 (48%) diploid malignant pleural effusions. Based on these results this type of DNA analysis had a sensitivity of 52% and a specificity of 100%. The mean (SD) numbers of flow cytometric S phase fractions of benign and malignant cases were 5.32 (1.67)% and 12.45 (3.93)% respectively. The mean numbers of S phase fractions of diploid malignant cases were higher than diploid benign cases. In each case the number of AgNORs was counted in 100 cells. The mean number of AgNOR dots per nucleus was 12.57 (3.64) for malignant pleural effusion cells and 3.96 (1.39) for benign pleural effusion cells. The mean number of AgNOR dots was 14.45 (3.36) for aneuploid malignant pleural effusion cells and 10.57 (2.82) for diploid malignant pleural effusion cells. The AgNOR numbers were higher in diploid malignant cells than in diploid benign cells. There was a significant correlation between the S phase fraction determined by flow cytometry and the mean number of AgNORs per nucleus in malignant cases.

CONCLUSIONS

Both flow cytometry and the AgNOR methods provide comparable measurements in the diagnosis of pleural effusion. The study also indicates that the AgNOR method, which is rapid and easy to perform, may be a useful adjunct to flow cytometry, S phase fraction analysis and conventional cytology in the routine diagnosis of malignant pleural effusion.

Value of DNA analysis in addition to cytological testing in the diagnosis of malignant pleural effusions

BACKGROUND

Aneuploidy appears to be a highly specific marker for cancer, and measurement of cellular DNA content by flow cytometry is rapid and reliable. This study was undertaken to determine if the addition of DNA analysis improved the sensitivity of cytological diagnosis of malignancy in pleural fluid.

METHODS

Pleural effusions from 92 patients were studied by cytological examination and flow cytometry.

RESULTS

In 41 patients the final diagnosis was malignancy, there were 40 cases of benign effusions including 22 with pleural tuberculosis, and in the remaining 11 patients with biopsy proven cancer the presence of malignant cells was not found by cytological and histological means in the pleural fluid. Aneuploidy and cytological malignancy were found in 14 samples. There were seven cases with abnormal flow cytometry and negative cytological results. In 12 patients the cytological test results were positive but DNA analysis was normal. Thirty six samples of fluid were both diploid and cytologically negative. Of the 22 tuberculous effusions seven contained aneuploid cells. The sensitivity of DNA and cytological analysis was 51.2% and 63.4%, respectively. The specificity of DNA analysis was 74.5%.

CONCLUSIONS

DNA analysis of cells in malignant pleural effusions is both less sensitive and specific than the cytological diagnosis. Flow cytometric analysis is not recommended for routine use in the diagnosis of pleural effusions.

Immunocytochemical typification of mesothelial cells in effusions: in vivo and in vitro models

We have performed immunocytochemical, immunoelectron microscopy, Western blot, and culture techniques using monoclonal antibodies against cytokeratin, vimentin, and desmin on 17 benign and 20 malignant effusions of pleural and ascitic origin. Triple coexpression of these three antigens was observed in benign reactive mesothelial cells as well as in one case of mesothelioma. All metastatic adenocarcinoma cells were consistently negative to desmin and positive to cytokeratin and vimentin. Present results were helpful to distinguish reactive and malignant mesothelioma from metastatic carcinoma cells in effusions.

Comparative assessment of DNA analysis in effusions by image analysis and flow cytometry

Cytologic evaluation of body cavity fluids is useful to detect malignancy within the pleural and peritoneal spaces. A definitive diagnosis cannot always be made on cytologic evaluation alone. As malignant processes may show abnormal DNA content, DNA analysis of effusions may be useful. Therefore, we determined the DNA content of 37 effusions by flow cytometry (FC) and image analysis (IA) using the CAS 200. Of the 37 fluids evaluated, 18 were cytologically malignant, 15 benign, and four atypical. Overall, 22 fluids (60%) showed concordance between FC and IA. None of the benign fluids were aneuploid. All showed diploid histograms or diploidy with increased proliferating cells. Three of four atypical fluids had increased proliferating cells by either FC or IA, whereas one was diploid by both methods. Aneuploidy was detected in 13 malignant fluids: five were aneuploid by both methods and eight by only one method. IA identified aneuploidy in five of those eight cases, while three were identified by FC. Three of the cytologically malignant fluids were diploid by both methods, and two showed increased proliferating cells by IA and diploidy by FC. The specificity of both methods was 100%. However, the sensitivity of identifying a malignant fluid by aneuploidy is low, 44% for FC and 55% for IA. IA appears to identify small aneuploid populations more frequently than FC. The detection of aneuploidy in effusions is highly suggestive of malignancy, and the combination of both techniques gives the highest detection rate (72%). However, neither are as sensitive as traditional cytologic evaluation with the occasional use of additional histochemical stains.

Flow cytometric evaluation of ovarian cancer

BACKGROUND

Despite recent advances in the treatment of ovarian cancer, the long-term prognosis for patients with this malignancy appears to depend more on tumor prognostic factors than on treatment regimens. The traditionally used prognostic factors are often subjective and, currently, have not been sufficient to determine individual patient prognosis.

METHODS

Newer techniques of quantitative cytologic testing, including flow cytometry, facilitate the objective evaluation of tumor cell heterogeneity and the identification of additional prognostic factors.

RESULTS

There is good evidence, mainly from retrospective studies, that DNA ploidy is a valuable prognostic indicator in patients with both early-stage and late-stage ovarian cancer. Most of the recent flow cytometric studies have identified ploidy as an independent prognostic factor, with aneuploidy predicting a significantly shorter survival time, even in patients with borderline malignant tumors. Flow cytometric determination of cell cycle information (e.g., S-phase fraction or proliferative index) may represent additional prognostic information and may be used to predict the early tumor response to treatment.

CONCLUSIONS

Although additional prospective studies are needed to establish the exact value of flow cytometric evaluation for ovarian cancer and other gynecologic malignancies, there is little doubt that the prognostic value of this information will influence clinical management of patients with these malignancies in the near future.

Immunocytometry and gene rearrangement analysis in the diagnosis of lymphoma in an idiopathic pleural effusion

We report a patient with an idiopathic pleural effusion in whom the diagnosis of non-Hodgkin's lymphoma was established by immunocytometry of pleural fluid and confirmed by the detection of B-cell immunoglobulin gene rearrangement. Immunocytometry is a rapid, semi-automated laboratory method for phenotyping lymphoid cells by determining immunoglobulin and other cell surface antigen expression. This method defines the cell lineage (T or B cells) and the clonality (monoclonal or polyclonal) of a population of lymphocytes. The presence of a monoclonal population of lymphocytes can also be confirmed by recently developed molecular biologic techniques (e.g., Southern blotting) that provide the ability to detect rearrangements of the genes that encode either B-cell immunoglobulin proteins or T-cell antigen receptor proteins. To our knowledge, this case represents the first reported application of immunophenotypic and gene rearrangement analysis in a previously undiagnosed pleural effusion to establish the diagnosis of lymphoma. These relatively new laboratory methods may have a role in the evaluation of idiopathic lymphocytic pleural effusions.

Flow cytometric DNA analysis versus cytology in the evaluation of peritoneal fluids

The use of flow cytometric DNA analysis as an adjunct to cytology in peritoneal fluid evaluation was studied. One hundred ninety-five fluids from 193 gynecologic patients were subjected to both DNA analysis and cytologic examination. It was found that 117/195 (60%) had invasive malignancies (50 ovarian, 48 endometrial, 17 cervical, and 2 miscellaneous); 34/117 (28%) patients with malignancies were positive by cytology, and 10/117 (8.5%) were positive (aneuploid) by DNA analysis. Of 34 cytologically positive cases, 7 (21%) were DNA positive, 25 (74%) were DNA negative, and in 2 (6%) insufficient cells were obtained. Only 3 fluids (3%) from malignancies were positive by flow cytometry and negative by cytology (1 stage I ovarian cancer, 1 stage I endometrial cancer, and 1 stage III ovarian cancer). No false-positive cytology and one probable false-positive flow result was obtained. If only those patients with histologically documented peritoneal involvement are considered, 29/43 (65%) had positive cytology and 8/43 (19%) had a positive flow result. We conclude that: (1) the high false-negative rate of flow cytometry (79%) versus cytology in this study may be related to a high percentage of diploid cancers, specimen preparation, or histogram interpretation, and (2) flow cytometry rarely adds to cytologic evaluation and is probably best reserved for use only in selected cases.

Evaluation of immunocytochemical staining as a method of improving diagnostic accuracy in a routine cytopathology laboratory

Immunocytochemical stains in a routine cytopathology laboratory can be used to distinguish between benign and malignant cells, and to identify tumour type. In our laboratory 30 problematic cases were selected for immunocytochemical stains and the results analysed in this paper. The following markers were used: cytokeratin (CAM5.2), carcinoembryonic antigen (CEA), kappa and lambda light chains, leucocytic common antigen (LCA), chorionic gonadotrophin (hCG), prostate specific antigen (PSA), L26, UCHL1, S100-protein and vimentin. Twelve FNA (four lymph nodes, one parotid swelling, two from lungs, two from pleura and chest wall, one from lumbar region, two from soft tissue masses), and 18 effusions (12 pleural effusions, five ascitic fluids, one pericardial effusion) were investigated. We found immunocytochemical stains of value in formulating the cytological diagnosis in 11/12 of FNA and 15/18 of effusions.

Cytophotometry in tumor pathology. A critical review of methods and applications, and some results of DNA analysis

In tumor pathology the quantitation of cellular substances can be of diagnostic value. Microscope cytophotometry and digital image analysis and, on the other hand, flow cytometry are supplementary methods for measuring, each with a typical spectrum of application. The methods are predominantly used for DNA analysis: Static and image cytophotometry are applicable to cytologic and histologic slides preferably for identifying stem lines in tumors of heterogenous morphology and in merely circumscribed lesions (e.g., precancerous lesions). On the other hand, sampling errors due to preselection, and the often low number of cells actually measured, may preclude the possibility of exact cell cycle analysis. This is, in fact, an important additional option of flow cytometry resulting from the high resolution of DNA histograms, which is explained by the large number of cells that can be measured in a short period. Sampling errors in flow cytometry may result from the preparation of single cell suspensions which in certain tumor entities may suppress a varying amount of particularly fragile cells or nuclei. The prognostic significance of DNA ploidy, stem line heterogeneity and S-phase fraction is clearly described in quite a number of tumor entities. Independent of its prognostic value, the cytometric identification of stem lines might be particularly useful in the follow-up of tumor patients, where it may indicate the effectivity of systemic therapy. The development of therapeutic concepts is aptly supported by flow cytometric cell cycle analysis which helps to assess the in vitro effect of combined cytostatics on the proliferative process. Moreover, multiparameter analysis of biopsy samples may provide greater accuracy in characterising individual tumor stem lines and may furthermore help to develop improved protocols for the therapy of solid tumors.

High-grade B-cell lymphoma presenting as polyserosal disease. Diagnosis by flow cytometry

Two patients presenting with anasarca were found to have aggressive B-cell lymphoma. No bulky disease was detected. The diagnosis was rapidly established by the flow cytometric analysis of cell surface immunophenotype and cell cycle fractions of pleural or peritoneal cells. Such presentation of lymphoma is unusual and previously undescribed, and it may have a significant negative prognostic impact. The authors' observations indicate that lymphoma be included in the differential diagnosis of anasarca and that flow cytometry can be useful for a fast confirmation of the diagnosis.

Flow cytometric analysis of cytologic specimens in hematologic disease

Cytologic evaluation of body fluids and fine needle aspirations (FNA) is frequently required in patients with hematologic diseases. In this study we have correlated immunophenotyping and DNA analysis by flow cytometry with cytologic findings and tissue biopsies from 20 patients with body fluid specimens and 5 with FNA. Nineteen of 25 cases, including all FNA cases, had an immunophenotype consistent with malignancy: 12 monoclonal B-cell lymphomas, 2 T-cell lymphomas, 2 T-ALL and 3 non-T-ALL. By cytologic examination, 14 of these 19 cases were positive for malignant cells, 2 suspicious and 3 negative; the latter 5 cases, including 2 FNA cases, had small monoclonal B-cell populations detected by flow cytometry. Six cases had a benign immunophenotype; cytologic examination was benign in 4 of these and suspicious for lymphoma in 2. Our results show the feasibility of using flow cytometry to evaluate body fluids or FNA and demonstrate that small malignant populations that may be missed by routine cytology can be detected by flow cytometry.

Value of immunocytochemistry in the study of malignant effusions

Recognition of malignant effusion relies heavily on cytologic examination despite the difficulty of distinguishing atypical mesothelial hyperplasia from metastatic carcinoma. The combination of CEA, EMA, vimentin, keratin, high-molecular-weight cytokeratin (HMWK), low-molecular-weight cytokeratin (LMWK), and Alcian blue was tested in 51 cytologic specimens of pleural, peritoneal, and pericardial effusions. These showed metastatic carcinoma in 38 cases (ovary, 14; lung, 8; breast, 7; GI, 4; endometrium, 4; bladder, 1) and mesothelial processes in 13 (hyperplasia, 9; mesothelioma, 4). Strong positivity for EMA (92%), CEA (90%), and Alcian blue (71%) was noted in metastatic carcinoma but not in the mesothelial processes. Keratin was positive in all cases of mesothelioma but occurred also in mesothelial hyperplasias (44%) and metastatic carcinomas (47%). In mesothelial cells, HMWK was consistently stronger than LMWK, whereas in adenocarcinoma the reverse was true. There was no difference in the degree or distribution of positivity of any of the markers among the various primary sites of the neoplasms. Our findings are consistent with the view that immunocytochemistry with a battery of antibodies is useful in the recognition of malignant effusions but cannot, as yet, determine the site of origin of metastatic neoplasms.

[Prospective comparison of the diagnostic value of cytology and immunocytology in pleural effusion studied by thoracoscopy and biopsy]

Two issues have been elaborated: the value of immunocytochemistry in the diagnosis of pleural effusions, and the reactivity of the investigated antibodies with different classes of cells in pleural effusions. Effusions of unknown origin from 38 patients were investigated using thoracoscopy, pleural biopsies, conventional cytology, and immunocytochemistry. The following antibodies were used: those monoclonal against various leukocyte antigens, macrophage antigens, epithelial membrane antigen (EMA), various cytoskeleton antigens, and melanoma antigens; those polyclonal against CEA and ferritin. All of the techniques used showed 18 patients (48%) as having a tumor-cell negative effusion. A pleural tumor with a malignant effusion showed in 13 patients (34%); in 12 of these immunocytochemistry also revealed tumor cells. Seven patients (18%) had a tumor of the pleura with a tumor-cell negative effusion; in 2 of these immunocytochemistry revealed a tumor-cell positive effusion. There was no difference with regard to the number of NK cells in patients with inflammation of the pleura and negative cytology and patients with tumor of the pleura and malignant effusion (3% vs 4.5%). Tumor cells were mainly stained by EMA, cytokeratin, and CEA. CEA was the only antibody to be tumor-cell specific, while EMA and cytokeratin were expressed by mesothelial cells also. The antibody against ferritin was a significant marker for mesothelial cells.

Flow cytometry and Feulgen cytophotometry in evaluation of effusions

Fifty-eight effusions (42 pleural and 16 ascitic fluids) from patients with and without cancer were analyzed by conventional cytology and the results compared with DNA patterns generated by flow cytometry of 10(4) nuclei and several modes of Feulgen cytophotometry. In 31 patients (24 without evidence of cancer and seven with history of cancer and cytologically negative fluids), the fluids were diploid by flow cytometry. One fluid with atypical cells from a lymphoma suspect was also diploid. Flow cytometry of 26 cytologically cancerous fluids disclosed aneuploid DNA patterns in 16 and diploid patterns in ten. Feulgen cytophotometry of 11 of these fluids (three aneuploid, eight diploid) was performed on nuclear preparations identical to those used in flow cytometry and on restrained smears used for visual analysis. The analysis was performed in two modes: as a study of 500 sequential nuclei in an automated system, mimicking flow cytometry, and visually selected large, presumably malignant nuclei. In nine of the 11 cases, the DNA content of visually selected cancer cells was aneuploid, even though this DNA pattern was not evident in the analysis of 500 sequential cells. In two cases, both diploid by flow cytometry, the Feulgen analysis confirmed the presence of cancer cells in the diploid range. In samples of 10(4) nuclei representing a mixed population of cells occurring in effusions, the presence of aneuploid cancer cells may not be disclosed by conventional flow cytometry. A larger sample of cells, a detailed analysis of DNA histograms, and perhaps sorting of select cells in the hypertetraploid range, may prove essential before flow cytometry can be accepted as a diagnostic tool in the laboratory in the assessment of effusions.

The karyological basis of atypia

There is no distinct DNA-pattern correlating with the degree of dysplasia. Atypical DNA-histograms can be found in morphologically normal smears especially when earlier smears had been suspicious. They can also persist after hysterectomy. In cases of progression aneuploidy and large scatter dominate while in cases of regression the DNA values are concentrated in the polyploid classes. Therefore, persisting atypical histograms signalize an increased risk in cases of dysplasia.

Severe Pericarditis as a Presenting Sign of Bronchogenic Carcinoma

An exudative pericarditis was the only sign of an adenocarcinoma arising from the right main bronchus of the lung for two and a half months. No metastases were found at the time of diagnosis. Pericarditis relapsed quickly after repeated pericardiocenteses, and systemic chemotherapy did not influence its course. Cardiac tamponade caused the death of the patient.