A simplified flow cytometric immunophenotyping procedure for the diagnosis of effusions caused by epithelial malignancies

Simple and rapid flow cytometry assay for the detection of malignant epithelial cells in body fluids

INTRODUCTION

Morphology is routinely used for detecting malignant cells in body fluids, but it has limitations. Recently, flow cytometry (FCM) is used as an effective tool for studying non-haematological malignancies. The main objective of this study is to standardize a simple and rapid FCM test for the detection of malignant epithelial cells in body fluids.

MATERIALS AND METHODS

Body fluids that had been processed for cytology/cytology and FCM were enrolled in this prospective study. We developed a fluorescent-labelled, monoclonal antibody panel composed of cell surface markers for this FCM assay. We compared the results of cytology/cell block and FCM.

RESULTS

A total of 121 fluid samples were studied. Comparing the diagnostic performance of cytology/cell block and FCM, 52 (43%) cases were positive and 60 (49.5%) cases were negative for carcinoma cells by both techniques. Nine cases showed discordant results between the two techniques. Six cases were cytology+ but FCM- and three cases were FCM+ cytology-. Clustered Epithelial Cell Adhesion Molecule (EpCAM)-positive events with high scatter properties were definitive for positive diagnosis by FCM. We studied PD-L1 expression in 13 cases by FCM. Six cases were reported as false negative by this FCM assay due to hypocellularity and lack of EpCAM expression in malignant cells.

CONCLUSIONS

This FCM assay is simple, easier and cost-effective yielding sensitive results with no inter-observer variability. FCM would become a valuable tool to complement routine diagnostic cytology and reduces misdiagnosis.

Cascaded elasto-inertial separation of malignant tumor cells from untreated malignant pleural and peritoneal effusions

Separation of malignant tumor cells (MTCs) from large background cells in untreated malignant pleural and peritoneal effusions (MPPEs) is critical for improving the sensitivity and efficiency of cytological diagnosis. Herein, we proposed a cascaded elasto-inertial cell separation (CEICS) device integrating an interfacial elasto-inertial microfluidic channel with a symmetric contraction expansion array (CEA) channel for pretreatment-free, high-recovery-ratio, and high-purity separation of MTCs from clinical MPPEs. First, the effects of flow-rate ratio, cell concentration, and cell size on separation performances in two single-stage channels were investigated. Then, the performances of the integrated CEICS device were characterized using blood cells spiked with three different tumor cells (MCF-7, MDA-MB-231, and A549 cells) at a high total throughput of 240 μL min-1. An average recovery ratio of ∼95% and an average purity of ∼61% for the three tumor cells were achieved. Finally, we successfully applied the CEICS device for the pretreatment-free separation of MTCs from clinical MPPEs of different cancers. Our CEICS device may provide a preparation tool for improving the sensitivity and efficiency of cytological examination.

Flow cytometry in the detection of circulating tumor cells in neoplastic effusions

PURPOSE

Despite its limitations, the cytology of body fluids is widely used in diagnosing neoplastic cells. Flow cytometry detects and identifies individual cells, enabling the detection of circulating tumor cells and facilitating diagnosis. This study compared the diagnostic utility of flow cytometry and cytology for detecting cancer cells in peritoneal and pleural fluids.

METHODOLOGY

We used flow cytometry and cytology to examine 119 pleural and peritoneal effusions received for routine screening. Antibodies against clusters of differentiation 45 (CD45), 14 (CD14), and Epithelial cell adhesion molecule (EpCAM) were used to detect malignant cells. Based on combined clinical and diagnostic information, 37 fluid specimens were malignant, and 77 were benign.

RESULTS

Flow cytometry correctly identified 34 cancers, while cytology identified 26 cancers (sensitivity 91.89 % vs. 70.27, respectively). Both methods had equal specificity (98.7 %). At a cut-off of > 0.29 % EpCAM(+) cells to all cells in the samples, flow cytometry accurately detected cancer cells, achieving 89.2 % sensitivity, 90.9 % specificity, and an AUC of 0.959 (p < 0.001).

CONCLUSION

Flow cytometry improves the detection of epithelial cancer cells in peritoneal and pleural fluids compared to conventional cytology. Due to similar specificity and higher sensitivity, flow cytometry offers a promising alternative to cytology for patient screening.

High sensitivity flow cytometry immunophenotyping increases the diagnostic yield of malignant pleural effusions

Diagnosing malignant pleural effusions (MPE) is challenging when patients lack a history of cancer and cytopathology does not detect malignant cells in pleural effusions (PE). We investigated whether a systematic analysis of PE by flow cytometry immunophenotyping (FCI) had any impact on the diagnostic yield of MPE. Over 7 years, 570 samples from patients with clinical suspicion of MPE were submitted for the FCI study. To screen for epithelial malignancies, a 3-color FCI high sensitivity assay was used. The FCI results, qualified as "malignant" (FCI+) or "non-malignant" (FCI-), were compared to integrated definitive diagnosis established by clinicians based on all available information. MPE was finally diagnosed in 182 samples and FCI detected 141/182 (77.5%). Morphology further confirmed FCI findings by cytopathology detection of malignant cells in PE (n = 91) or histopathology (n = 29). Imaging tests and clinical history supported the diagnosis in the remaining samples. The median percentage of malignant cells was 6.5% for lymphoma and 0.23% for MPE secondary to epithelial cell malignancies. FCI identified a significantly lower percentage of EpCAM+ cells in cytopathology-negative MPE than in cytopathology-positive cases (0.02% vs. 1%; p < 0.0001). Interestingly, 29/52 MPE (55.8%) where FCI alerted of the presence of malignant cells were new diagnosis of cancer. Overall, FCI correctly diagnosed 456/522 samples (87.4%) suitable for comparison with cytopathology. These findings show that high sensitivity FCI significantly increases the diagnostic yield of MPE. Early detection of FCI + cases accelerates the diagnostic pathway of unsuspected MPE, thus supporting its implementation in clinical diagnostic work-up as a diagnostic tool.

Diagnostic accuracy of flow cytometry in detecting malignant epithelial cells in serous effusions

INTRODUCTION

This study aims to evaluate diagnostic accuracy of flow cytometry (FCM) in detecting malignant epithelial cells in serous effusions.

MATERIALS AND METHODS

Flow cytometric assessment of 96 serous fluids (86 ascitic, 10 pleural) was performed by using epithelial cell adhesion molecule (EpCAM) (in all 96 fluids) and MUC-1 (in a subgroup of 40 fluids) as epithelial markers and CD45 and CD14 as leucocyte markers. The percentage of EpCAM positivity and MUC-1 positivity was calculated in the CD14 and CD45 dual negative population by selective gating. The findings were then correlated with the defined gold standard criteria.

RESULTS

The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy for EpCAM was found to be 92.06%, 96.96%, 98.31%, 86.48%, and 93.75%, respectively, while that for MUC-1 was 79.16%, 93.75%, 95%, 71.4%, and 85%, respectively. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy for dual positivity for EpCAM and MUC-1 was found to be 83.3%, 100%, 100%, 80%, and 90% respectively. On combining FCM with cytomorphology the sensitivity, specificity, PPV, NPV, and diagnostic accuracy all increased greatly to 95.3%, 100%, 100%, 91.4%, and 96.8%, respectively.

CONCLUSIONS

This study highlights the importance of multicolored flow cytometric analysis in detecting epithelial malignancies in effusions specially in cases belonging to the atypia of undetermined significance and suspicious for malignancy categories and in cases with strong clinical suspicion of malignancy with negative fluid cytology. We recommend the combined use of FCM and cytology for this specific subgroup of patients in routine clinical practice for fast and accurate reporting.

Utility of Flow Cytometry Analysis in the Detection of Nonhematologic Neoplasms: An Overview

Flow cytometry analysis has stood the test of time as a powerful tool in the assessment of hematologic neoplasms. The role of flow cytometry has expanded to evaluate various nonhematologic neoplasms encountered in body cavity malignant effusions, lymph nodes, and other body sites. This review explores the use of routine antibody panels as well as specially designed multicolor antibody panels that have been investigated by different groups and reported in the literature for evaluating nonhematologic neoplasms. In this context, the limitations, pitfalls, future directions, and promising applications of flow cytometry analysis are also discussed.

High-Throughput Separation and Enrichment of Rare Malignant Tumor Cells from Large-Volume Effusions by Inertial Microfluidics

Detection of malignant tumor cells (MTCs) in pleural effusions is essential for determining the malignancy. However, the sensitivity of MTC detection is significantly decreased due to the existence of a massive number of background blood cells in large-volume samples. Herein, we provide a method for on-chip separation and enrichment of MTCs from malignant pleural effusions (MPEs) by integrating an inertial microfluidic sorter with an inertial microfluidic concentrator. The designed sorter and concentrator are capable of focusing cells toward the specified equilibrium positions by inducing intrinsic hydrodynamic forces, enabling the size-based sorting of cells and the removal of cell-free fluids for cell enrichment. A 99.9% removal of background cells and a nearly 1400-fold ultrahigh enrichment of MTCs from large-volume MPEs can be achieved by this method. The concentrated high-purity MTC solution can be used directly for cytological examination by immunofluorescence staining, enhancing the accurate identification of MPEs. The proposed method can also be employed for the detection and count of rare cells in various clinical samples.

Routine flow cytometry approach for the evaluation of solid tumor neoplasms and immune cells in minimally invasive samples

BACKGROUND

Multidimensional flow cytometry (MFC) is routinely used for the diagnosis and follow-up of hematolymphoid neoplasms but its contribution to the identification of non-hematolymphoid malignant tumors is limited.

METHODS

The presence of non-hematolymphoid cells in clinical samples obtained via minimally invasive methods was ascertained by using a panel of monoclonal antibodies previously developed in our laboratory comprising a mixture of antibodies: CD9-PacB/CD45-OC515/CD57-FITC/CD56-PE/CD3-PerCP-Cy5.5/CD117-PE-Cy7/CD326-APC/CD81-APC-C750. Histopathological studies were performed using standard techniques.

RESULTS

164 specimens of different origins were included. Malignancy was finally confirmed in 142 (86.5%), while 22 non neoplastic samples were identified. The most frequent diagnosis was small cell lung carcinoma (SCLC) (50%). High sensitivity (S = 98.6%) was reached combining MFC and conventional pathology. Individual markers differed according to the cellular origin of the neoplasm, with neuroendocrine tumors showing a unique immunophenotypic profile (CD56+ CD326+ CD117-/+ and variable tetraspanins expression). Principal component analysis efficiently distinguished SCLC from other tumor samples. In immune cell populations, differences between reactive and malignant biopsies were found in different cell compartments, especially in B cells and Plasma cells. Differences also emerged in the percentage of CD4+ CD8- T cells, CD4-CD8+ T cells and NK cells and these were dependent on the origin of the tumor cells.

CONCLUSIONS

These results support the use of MFC as a rapid and valuable technique to detect non-hematolymphoid tumoral cells in clinical specimens, providing an initial orientation to complement hystopathological studies and allow a more precise diagnosis, especially in neuroendocrine neoplasms. The impact of different immune cell patterns warrants further research.

Flow Cytometric Findings in Primary Effusion Lymphoma: A Report of Two Cases

Primary effusion lymphoma (PEL) is a rare B-cell lymphoma that usually occurs in the setting of HIV infection, and it is associated with Human Herpesvirus-8 (HHV-8). Diagnosis of PEL is usually established in cell centrifuge, cell block, or tissue examination, and there are few reports describing flow cytometry findings in PEL. We report two male patients (a 34-year-old and a 56-year-old) with a history of HIV infection. The first patient presented with ascites and abdominal pain, and the second patient presented with chest pain and parapneumonic pleural effusion. Cavitary fluid examination showed large pleomorphic neoplastic lymphoid cells with plasmablastic morphology. Flow cytometry analysis of the neoplastic lymphocytes showed increased forward scatter and side scatter with intermediate to a high level of CD38 expression. In one patient, lymphoma cells showed bright CD45 expression with dim expression of CD19 and kappa light chain. There was no significant expression of CD20 or any T/NK cell markers in either case. Immunohistochemistry for CD30 was positive in one patient. Immunohistochemistry for HHV-8 and in situ hybridization for Epstein-Barr virus-encoded small RNAs (EBER) was positive on cell blocks in both cases, consistent with the diagnosis of primary effusion lymphoma. PEL should be considered in the differential diagnosis of CD20-negative hematopoietic neoplasms, and flow cytometry may provide helpful clues for the diagnosis of PEL as part of the workup for pleural effusion with cytologically malignant cells.

High-throughput and label-free enrichment of malignant tumor cells and clusters from pleural and peritoneal effusions using inertial microfluidics

Accurate and rapid diagnosis of malignant pleural and peritoneal effusions is critical due to potential association with advanced disease stages or progression. Traditional cytodiagnosis suffers from low efficiency and has difficulties in finding malignant tumor cells (MTCs) from a mass of exfoliated cells. Hence, a polymer microfluidic chip with a slanted spiral channel was employed for high-throughput and label-free enrichment of MTCs and MTC clusters from clinical malignant pleural and peritoneal effusions. The slanted spiral channel with trapezoidal cross-sections was fabricated by assembling two patterned polymer films of different thicknesses within one flow channel layer. After systematically exploring the effects of the particle size, effusion concentration, and flow rate on separation performance of the device, we realized the enrichment of MTCs from abundant blood cells in 2-fold diluted effusions. The results indicated that approximately 85% of the spiked tumor cells (A549 and MCF-7 cell lines) were recovered with high purities of over 37% at a high throughput of 2000 μL min^-1. In clinical applications, we successfully enriched 24-2691 MTCs per mL from the diluted malignant pleural and peritoneal effusions collected from four types of cancer patients (n = 22). More importantly, the MTC clusters were further purified from single MTCs using a higher flow rate of 3000 μL min^-1. Finally, we performed the rapid drug sensitivity test by coupling the microfluidic enrichment with CCK-8 assay. Our approach may serve as valuable assistance to accelerate cancer diagnosis and guide the selection of treatment medications.

Flow cytometry-based analysis of tumor-leukocyte ratios in peritoneal fluid from patients with advanced gastric cancer

Background

The frequency of tumor cell dissemination in the peritoneal cavity is critically related to the progression of peritoneal metastases (PM). Recently, flow cytometry (FCM) has been successfully used to detect tumor cells in malignant effusions.

Methods

A total of 143 single cell suspensions derived from ascites or peritoneal lavages from patients with advanced gastric cancer (GC) were stained with monoclonal antibodies to CD45 and to CD326 as well as 4,6‐diamidino‐2‐phenylindole (DAPI) and FVS780. Using FCM, tumor‐leukocyte ratio (TLR) were calculated from CD45(−)CD326(+) tumor cell counts/ CD45(+)CD326(+) leukocyte counts in DAPI (+) FVS780(−) gated area. In 54 patients, the ratios of CD11b(+), CD4(+) and CD8(+) cells in CD45(+) leukocytes were evaluated in parallel.

Results

TLR of 69 patients with PM were significantly higher than those of 74 without PM (p < .001) and log(TLR) showed strong correlation with peritoneal cancer index scores in 51 PM (+) patients (r = 0.439). TLR in PM (+) patients also correlated with the ratio of CD11b (+) myeloid cells (r = 0.547), and correlated inversely with those of CD4(+) (r = −0.490) and CD8(+) T cells (r = −0.648). In PM (−) patients who underwent gastrectomy, TLR never exceeded 0.1% in patients with primary GC without serosal involvement (<T4). However, TLR in patients with T4 GC were significantly higher (p < .05) and peritoneal recurrence occurred in 6/8 patients whose TLR exceeded 0.1%.

Conclusion

TLR in peritoneal fluid reflects tumor burden and the immune environment in peritoneal cavity. Multicolor FCM may provide additional information which can be used for the treatment of the patients with PM.

Application of multicolour flow cytometry in the detection of metastatic carcinoma in serous effusions: Special emphasis in atypical cytology

INTRODUCTION

We evaluated the role of simultaneous use of multiple antibodies in flow cytometry (FCM) to detect metastatic carcinomas in effusion samples.

METHODS

Cytological examination of 75 successive cases of effusion samples was performed. There were 48 peritoneal, 26 pleural and one pericardial fluid. Multi-coloured FCM examination was undertaken using a cocktail of CD45, CD14 and epithelial cell adhesion molecule (EpCAM), antibodies tagged with different fluorochromes. The percentage of EpCAM positivity was calculated in the CD45 and CD14 dual negative population by selective gating. The EpCAM value was correlated with the cytological findings, follow-up data and MOC-31 immunostaining.

RESULTS

There were 20 benign, 35 malignant and 20 atypical cases diagnosed on cytomorphology. The primary sources of carcinomas were mainly from the ovary, followed by lung, gall bladder, intestine and other areas. Out of 20 cytologically benign cases, there were two malignant cases on the final follow-up, and EpCAM on FCM picked up all 18 benign cases and one malignant case. Out of 35 cytologically detected malignant cases, EpCAM picked up 32 malignant cases. The EpCAM detected 15/18 malignant and both benign cases out of 20 cytological atypical cases. EpCAM antibody by FCM showed 87% sensitivity, 100% specificity, 100% positive predictive value and 74% negative predictive value.

CONCLUSION

This comprehensive study highlights the potential use of multi-coloured FCM along with cytological examination to diagnose metastatic carcinoma in effusion samples. Multi-coloured FCM is rapid and quantitative and is helpful in atypical cases.

Rapid purification of lung cancer cells in pleural effusion through spiral microfluidic channels for diagnosis improvement

Lung cancer is one of the leading causes of death worldwide. Fifteen percent of lung cancer patients will present with malignant pleural effusion initially, and up to 50% will have malignant pleural effusion throughout the course of the disease. In this study, we developed a spiral microfluidic device that can rapidly isolate cancer cells and improve their purity through fluid dynamics. This label-free, high-throughput device continuously isolates cancer cells and other unrelated molecules from pleural effusion. Most of the background cells that affect interpretation are flushed to outlets 1 to 3, and cancer cells are hydrodynamically concentrated to outlet 4, with 90% of lung cancer cells flowing to this outlet. After processing, the purity of cancer cells identified in pleural effusion by CD45 and epithelial cell adhesion molecule (EpCAM) antibodies in flow cytometry will be increased by 6 to 24 times. The microfluidic device presented here has the advantages of rapid processing and low cost, which are conducive to rapid and accurate clinical diagnosis.

Application of flow cytometry in the analysis of lymphoid disease in the lung and pleural space

Various types of lymphoid neoplasms can occur in the lung. Lung parenchyma, the pleura or the pleural cavity can be the primary site of a lymphoid neoplasm or can be involved secondarily as a result of systemic dissemination from a separate primary site. Recognition of pulmonary lymphoid neoplasms (PLN) has increased secondary to technological advances in the medical field. Multiparameter flow cytometry (FC) is a one of the diagnostic tools that serves an essential role in the detecting and categorizing PLNs. FC allows for rapid identification and immunophenotypic characterization of PLN. In this article, we discuss the role of FC in the diagnosis of the most commonly encountered PLNs as well as their basic clinicopathologic features. We briefly discuss the role of FC in identifying non-hematolymphoid neoplasms in lung specimens as well.

Detection of small numbers of iPSCs in different heterogeneous cell mixtures with highly sensitive droplet digital PCR

Induced pluripotent stem cells (iPS cells) are a prospective resource for regenerative biomedicine. iPS cells can differentiate into any type of stem, progenitor and somatic cells to help replace structures within damaged organs or tissues. However, iPS cells themselves, can produce malignant tumors if they are injected into the body of an immunocompatible or immunodeficient recipient. Thus, it is necessary to detect any residual iPS cells content in biomedical cell products obtained from iPS cells and destined for transplantation. In this article we describe searches for iPS cells in heterogeneous cell mixtures, using two different methods-quantitative RT-PCR and droplet digital PCR (ddPCR). In experiments with various heterogeneous mixtures, including mixtures with neural stem cells, we found that the OCT4, TDGF1 and LIN28 genes are the best markers for such a search, and droplet digital PCR provides the greatest measurement accuracy, which is 0.002%. Thus, we have confirmed the advantage of using droplet digital PCR in the search for pluripotent stem cells in heterogeneous cell mixtures. We hope that this data can be useful for biosafety control in regenerative biomedicine.

ERS/EACTS statement on the management of malignant pleural effusions

Malignant pleural effusions (MPE) are a common pathology, treated by respiratory physicians and thoracic surgeons alike. In recent years, several well-designed randomized clinical trials have been published that have changed the landscape of MPE management. The European Respiratory Society (ERS) and the European Association for Cardio-Thoracic Surgery (EACTS) established a multidisciplinary collaboration of clinicians with expertise in the management of MPE with the aim of producing a comprehensive review of the scientific literature. Six areas of interest were identified, including the optimum management of symptomatic MPE, management of trapped lung in MPE, management of loculated MPE, prognostic factors in MPE, whether there is a role for oncological therapies prior to intervention for MPE and whether a histological diagnosis is always required in MPE. The literature revealed that talc pleurodesis and indwelling pleural catheters effectively manage the symptoms of MPE. There was limited evidence regarding the management of trapped lung or loculated MPE. The LENT score was identified as a validated tool for predicting survival in MPE, with Brims' prognostic score demonstrating utility in mesothelioma prognostication. There was no evidence to support the use of oncological therapies as an alternative to MPE drainage, and the literature supported the use of tissue biopsy as the gold standard for diagnosis and treatment planning.Management options for malignant pleural effusions have advanced over the past decade, with high-quality randomized trial evidence informing practice in many areas. However, uncertainties remain and further research is required http://ow.ly/rNt730jOxOS.

Are we ready to develop a tiered scheme for the effusion cytology? A comprehensive review and analysis of the literature

BACKGROUND

Cytology is widely utilized in the initial evaluation of fluid accumulation in the body cavities. The aim of this study was to determine the accuracy of cytology in distinguishing between benign and malignant (MAL) effusions.

METHODS

A comprehensive and systematic review of the literature was conducted to evaluate the accuracy of serous effusion cytology (SEC) against tissue biopsy/resection histology, imaging, or clinical follow-up as the reference test. Risk of publication bias and level of heterogeneity in the included studies was assessed. Meta-regression was performed to assess the effect of various variables on the accuracy of SEC.

RESULTS

Eighty studies met the inclusion criteria for meta-analysis comprising of 34 941 samples; of which 52 (0.2%), 22 202 (72.7%), 194 (0.6%), 711 (2.3%), and 6507 (21.3%) could be reclassified as nondiagnostic (ND), negative for malignancy (NFM), atypical (atypia of uncertain significance-AUS), suspicious for malignancy (SFM), and malignant (MAL), respectively. On follow-up, the mean risk of malignancy for ND, NFM, AUS, SFM, MAL was 17.4%, 20.7%, 65.9%, 81.8%, and 98.9%, respectively. A total of 73 studies were included in estimating the diagnostic accuracy of SEC. The bivariate mixed-effect model estimated the SEC sensitivity, specificity, diagnostic odds ratio, positive likelihood ratio, and negative likelihood ratio as 73.1%, 99.9%, 7850.6%, 2112.2%, and 0.27%, respectively.

CONCLUSION

Serous effusion cytology shows high specificity and moderate sensitivity in the evaluation of serous effusions. A tiered classification scheme can improve the consistency of terminology for reporting SEC results, thus improving communication between the pathologists and clinical team, and quality of patient care.

Epithelial cell adhesion molecule (EpCAM) from pleural fluid cell lysates is a highly accurate diagnostic biomarker of adenocarcinomatous effusions

BACKGROUND AND OBJECTIVE

The discovery of highly accurate pleural fluid (PF) biomarkers of malignancy remains elusive. We assessed the operating characteristics of the PF epithelial cell adhesion molecule (EpCAM), claudin 4 (CL4) and human epididymis protein 4 (HE4) as potential markers of epithelial malignancies.

METHODS

The three markers were quantified by immunoassays in the supernatants (s) and cell lysates (cl) of 175 PF samples. The cut-off values with 100% specificity were selected for malignant-benign discrimination. An immunocytochemical staining index score for each marker was also evaluated on PF cell blocks. The resulting best biomarker was further validated in two independent populations of 73 and 48 patients with pleural effusions (PE).

RESULTS

An EpCAM(cl) >98 pg/g total lysate protein yielded 75% sensitivity, 100% specificity, negative likelihood ratio of 0.25 and area under the curve of 0.94 for labelling adenocarcinomatous effusions. Sensitivity reached 88% if EpCAM(cl) was combined with EpCAM immunostaining. One-third or more of the malignant effusions exhibiting a false-negative cytological fluid examination were correctly classified by EpCAM(cl) concentrations. Immunoassays for CL4 and HE4 were diagnostically useless.

CONCLUSION

EpCAM(cl) is a new biomarker of adenocarcinomatous PE with meaningful discriminating properties.

Flow cytometry identification of nonhemopoietic neoplasms during routine immunophenotyping

INTRODUCTION

Nonhemopoietic neoplasms (NHNs) may be encountered during routine flow cytometry (FC) immunophenotyping. The clue of their presence mainly relies on detection of CD45-negative (CD45-) cells with altered scatter parameters.

METHODS

In this study, we evaluated a monoclonal antibody combination conceived to characterize the CD45- population by FC, suspected of belonging to NHNs, when present. The panel included CD45 for leucocytes identification, CD326 (clones BerEP4 and HEA-125) to mark epithelial cells, CD33 to identify myeloid cells, CD138 to trace plasma cells and CD56 useful in the identification of neuroendocrine tumours. 7AAD vital dye was used to gate out dead cells. Results were correlated with cytomorphology and confirmed by histological data, if available.

RESULTS

Among 9422 specimens submitted for routine FC investigation, 47 samples that included fine-needle aspirates, bone marrow aspirates, tissue biopsies and body fluids had a detectable CD45- population and a sufficient cell amount to be further investigated. FC revealed the presence of CD326-positive epithelial cells in 38 specimens; altered scatter parameters and variable reactivity to the other antigens tested allowed to suspect NHNs in the remaining nine samples. The presence of NHNs was confirmed in all cases by morphology.

CONCLUSIONS

The current results show that when CD45- cells with altered scatter parameters were detected, cytometrists involved in leukaemia/lymphoma diagnosis may require further FC investigations to rapidly identify NHNs in different specimens, thus reducing the time of the immunohistochemical diagnostic workup to reach a final diagnosis.

ERS/EACTS statement on the management of malignant pleural effusions

Malignant pleural effusions (MPE) are a common pathology, treated by respiratory physicians and thoracic surgeons alike. In recent years, several well-designed randomised clinical trials have been published that have changed the landscape of MPE management. The European Respiratory Society (ERS) and the European Association for Cardio-Thoracic Surgery (EACTS) established a multidisciplinary collaboration of clinicians with expertise in the management of MPE with the aim of producing a comprehensive review of the scientific literature.

Six areas of interest were identified, including the optimum management of symptomatic MPE, management of trapped lung in MPE, management of loculated MPE, prognostic factors in MPE, whether there is a role for oncological therapies prior to intervention for MPE and whether a histological diagnosis is always required in MPE.

The literature revealed that talc pleurodesis and indwelling pleural catheters effectively manage the symptoms of MPE. There was limited evidence regarding the management of trapped lung or loculated MPE. The LENT score was identified as a validated tool for predicting survival in MPE, with Brims' prognostic score demonstrating utility in mesothelioma prognostication. There was no evidence to support the use of oncological therapies as an alternative to MPE drainage, and the literature supported the use of tissue biopsy as the gold standard for diagnosis and treatment planning.

Validating Micronucleus Score in Effusion Fluids

Background:

Identifying malignant cells in effusion fluid is vital in staging and management of cancers. Differentiating reactive mesothelial cells from malignant cells in effusion fluid is a challenging task and there is an ongoing need for simpler and cost effective tool to aid the diagnosis. Micronucleus is an additional smaller nucleus in the cytoplasm, formed by chromosomes or chromosomal fragments formed during cell division.

Aims:

The aim of this study was to assess the significance of micronucleated cell in effusion fluids to distinguish adenocarcinomatous from reactive mesothelial effusions.

Materials and Methods:

Thirty cases of unequivocal malignant effusion fluids and 30 benign cases with reactive mesothelial cells as control were studied. Number of microucleated cells present per1000 well-preserved cells in Leishman-stained smears were counted.

Results:

Mean (±SD) micronucleated score in malignant and benign effusions were 15.77 ± 9.78 and 1.87 ± 1.78, respectively. The median scores were 13 and 2, respectively. Mann–Whitney test showed that this difference was statistically significant (P < 0.001). This study revealed that there was a significant difference in micronucleus scoring between benign and malignant effusions.

Conclusions:

Micronucleus score can be used as an additional biomarker in the interpretation of routinely stained cytosmears.

Single-Tube Flow Cytometry Assay for the Detection of Mature Lymphoid Neoplasms in Paucicellular Samples

OBJECTIVES

Flow cytometry (FC) has become a useful support for cytomorphologic evaluation (CM) of fine-needle aspirates (FNA) and serous cavity effusions (SCE) in cases of suspected non-Hodgkin lymphoma (NHL). FC results may be hampered by the scarce viability and low cellularity of the specimens.

STUDY DESIGN

We developed a single-tube FC assay (STA) that included 10 antibodies cocktailed in 8-color labeling, a cell viability dye, and a logical gating strategy to detect NHL in hypocellular samples. The results were correlated with CM and confirmed by histologic or molecular data when available.

RESULTS

Using the STA, we detected B-type NHL in 31 out of 103 hypocellular samples (81 FNA and 22 SCE). Of these, 8 were not confirmed by CM and 2 were considered to be only suspicious. The FC-negative samples had a final diagnosis of benign/reactive process (42/72), carcinoma (27/72), or Hodgkin lymphoma (3/72).

CONCLUSIONS

The STA approach allowed obtainment of maximum immunophenotyping data in specimens containing a low number of cells and a large amount of debris. The information obtained by STA can help cytomorphologists not only to recognize but also to exclude malignant lymphomas.

Flow Cytometry of Nonhematopoietic Neoplasms

Many epithelial neoplasms can be analyzed by flow cytometry (FC), particularly from serous cavity effusion samples, using EpCAM, a cell adhesion molecule expressed on most normal epithelial cells and expressed at a higher level in most epithelial neoplasms. A simple 3-color flow cytometric panel can provide a high sensitivity and specificity compared to cytomorphology. FC provides more rapid immunophenotyping than conventional immunohistochemical staining, can identify rare malignant cells that could be missed by a cytological exam alone, and can be utilized to evaluate limited samples such as cerebrospinal fluid or fine-needle aspiration samples. Flow cytometric analysis for epithelial antigens can be combined with DNA ploidy analysis or assessment of the nucleus-to-cytoplasm ratio. Panels of flow cytometric markers are useful for the assessment of pediatric nonhematopoietic neoplasms, including neuroblastomas, primitive neuroectodermal tumors, Wilms' tumor, rhabdomyosarcomas, germ cell tumors, and hemangiopericytomas, as well as small-round-blue-cell tumors in adults, including small-cell carcinomas.

Malignant Nonhematological Effusion Characterization by Flow Cytometry

With the exception of hematological malignancies, flow cytometry (FC) is infrequently applied as an ancillary tool in the diagnosis of malignant effusions in most institutions. However, FC may be effectively used to differentiate between epithelial cells, mesothelial cells and leukocytes using antibodies against both cell surface and intracellular proteins, offering the advantage of quantitative analysis. Additionally, FC may be applied to the quantitative detection of cancer-associated molecules, including stem cell markers, as well as assessment of critical cellular processes, such as proliferation and apoptosis. Some of the latter tests may have relevance for monitoring treatment response in the presence of metastatic disease, although this does not constitute routine practice to date. This review summarizes current knowledge regarding the application of FC to serous effusions in the diagnostic setting, as well as in research into cancer biology focusing on clinical specimens. The studies published to date suggest a role for this method in the clinical setting in the context of diagnosis, prediction and prognosis.

Diagnostic and prognostic significance of flow cytometry immunophenotyping in patients with leptomeningeal carcinomatosis

Some patients with epithelial-cell cancers develop leptomeningeal carcinomatosis (LC), a severe complication difficult to diagnose and with an adverse prognosis. This study explores the contribution of flow cytometry immunophenotyping (FCI) to the diagnosis and prognosis of LC. Cerebrospinal fluid (CSF) samples from patients diagnosed with LC were studied using FCI. Expression of the epithelial-cell adhesion molecule (EpCAM) was the criterion used to identify the epithelial cells. To test the diagnostic precision, 144 patients (94 diagnosed with LC) were included. The prognostic value of FCI was evaluated in 72 patients diagnosed with LC and eligible for therapy. Compared with cytology, FCI showed greater sensitivity and negative predictive value (79.79 vs. 50%; 68.85 vs. 51.55%, respectively), but lower specificity and positive predictive value (84 vs. 100%; 90.36 vs. 100%, respectively). The multivariate analysis revealed that the percentage of CSF EpCAM+ cells predicted an increased risk of death (HR: 1.012, 95% CI 1.000-1.023; p=0.041). A cut-off value of 8% EpCAM+ cells in the CSF distinguished two groups of patients with statistically significant differences in overall survival (OS) (p=0.018). This cut-off value kept its statistical significance regardless of the absolute CSF cell-count. The FCI study of the CSF improved the sensitivity for diagnosing LC, but refinement of the technique is needed to improve specificity. Furthermore, quantification of CSF EpCAM+ cells was revealed to be an independent prognostic factor for OS in patients with LC eligible for therapy. An 8% cut-off value contributed to predicting clinical evolution before initiation of therapy.

Lung cancer coexisting with ipsilateral pleural effusion

SUMMARY 

Invasion beyond the elastic layer of the visceral pleura and/or diffuse pleural metastatic spread affects negatively survival in lung cancer. Presence of pleural effusion is also associated with poor prognosis, and image techniques can be of great help for diagnosis. When pleural fluid cytology is negative, thoracoscopy is advisable before attempting tumor resection, in order to detect unsuspected pleural metastases. If widespread pleural malignancy is confirmed, chemical pleurodesis using graded talc (with particles larger than 20 µm in diameter) is the best option, unless the lung is unable to re-expand. In this case, or when a previous pleurodesis has failed, or there is a short life expectancy, placement of a indwelling pleural catheter is the treatment of choice.