A prospective study of the volume of pleural fluid required for accurate diagnosis of malignant pleural effusion

Risk of Malignancy in Effusions according to the International System for Serous Fluid Cytopathology: A Review

INTRODUCTION

The International Serous Fluid Cytopathology Reporting System (TIS) was developed to standardize communication among health professionals reporting analyses of serous fluid samples. The categories include non-diagnosis (ND), negative for malignancy (NFM), atypia of undetermined significance (AUS), suspected malignancy (SFM), and malignant (MAL). Each category was characterized by a risk of malignancy (ROM).

METHODS

We performed a literature review to analyze studies related to TIS using several sources, including PubMed, followed by a search of relevant cytopathology journal websites (American Cancer Society, Diagnostic Cytopathology, Journal of the American Society of Cytopathology, and Acta Cytologica and Cytopathology). The search included articles published between January 2020 and December 2023, using the terms "international AND serous fluid system."

RESULTS

We identified 257 articles, of which 20 addressed the inclusion and exclusion criteria. The overall ROMs for each category were 23.55% for ND, 16.46% for NFM, 50.78% for AUS, 91.34% for SFM, and 98.21% for MAL.

CONCLUSION

Considering the TIS-recommended ROM rates, the ND category was between the suggested intervals, while the SFM category rate was bigger than expected. The other categories (NFM, AUS, and MAL) were below expected values. SFM and MAL had a stronger association with MAL results. New studies are needed to determine each category's ROM rate from TIS accurately.

Optimal Volume Assessment for Serous Fluid Cytology

OBJECTIVE

This study aimed to investigate the optimal volume of serous fluid needed for accurate diagnosis using The International System for Reporting Serous Fluid Cytopathology (TIS), as well as to provide information on the distribution of serous effusion cases in the TIS categories (ND: non-diagnostic, NFM: negative for malignancy, AUS: atypia of undetermined significance, SFM: suspicious for malignancy, MAL: malignant) and relevant epidemiological data.

METHODS

A retrospective analysis of 2340 serous effusion cases (pleural, peritoneal, and pericardial) from two hospitals between 2018 and 2020 was conducted. TIS categories were assigned to each case, and for 1181 cases, these were correlated with the volume of the analyzed fluid.

RESULTS

Our study found statistically significant differences in volume distributions between certain TIS categories. Statistically lower volumes were observed in NFM compared to MAL, in UNCERTAIN (ND, AUS, SFM) compared to both MAL and NFM, and in NOT MAL (ND, NFM, AUS, SFM) compared to MAL. However, these differences were not substantial enough to hold any clinical relevance.

CONCLUSIONS

This study suggests that while fluid volume may slightly influence the TIS category, it does not impact the diagnostic accuracy of serous effusion cytology. Therefore, the ideal serous effusion specimen volume can be defined solely by practical parameters.

Malignant pleural effusion: current understanding and therapeutic approach

Malignant pleural effusion (MPE) is a common complication of thoracic and extrathoracic malignancies and is associated with high mortality and elevated costs to healthcare systems. Over the last decades the understanding of pathophysiology mechanisms, diagnostic techniques and optimal treatment intervention in MPE have been greatly advanced by recent high-quality research, leading to an ever less invasive diagnostic approach and more personalized management. Despite a number of management options, including talc pleurodesis, indwelling pleural catheters and combinations of the two, treatment for MPE remains symptom directed and centered around drainage strategy. In the next future, because of a better understanding of underlying tumor biology together with more sensitive molecular diagnostic techniques, it is likely that combined diagnostic and therapeutic procedures allowing near total outpatient management of MPE will become popular. This article provides a review of the current advances, new discoveries and future directions in the pathophysiology, diagnosis and management of MPE.

High Yield of Pleural Cell-Free DNA for Diagnosis of Oncogenic Mutations in Lung Adenocarcinoma

BACKGROUND

Pleural cytology is currently used to assess targetable mutations in patients with advanced lung adenocarcinoma. However, it is fraught with low diagnostic yield.

RESEARCH QUESTION

Can pleural cell-free DNA (cfDNA) be used to assess targetable mutations in lung adenocarcinoma patients with malignant pleural effusions (MPE)?

STUDY DESIGN AND METHODS

Patients with lung adenocarcinoma MPE were recruited prospectively between January 2017 and September 2021. Oncogenic mutations were assessed by treating providers using pleural fluid cytology or lung cancer biopsies. Pleural and plasma cfDNA were used to assess the mutations using next-generation sequencing (NGS).

RESULTS

Fifty-four pleural fluid samples were collected from 42 patients. The diagnostic yield to detect oncogenic mutations for pleural cfDNA, pleural cytology, biopsy, and plasma cfDNA was 49/54 (90.7%), 16/33 (48.5%), 22/25 (88%), and 24/32 (75%), respectively, P < .001. The agreement of mutations in positive samples between pleural cfDNA and pleural cytology was 100%, whereas the agreement of pleural cfDNA with biopsies was 89.4%. The median concentration (interquartile range) of pleural cfDNA was higher than plasma: 28,444 (4,957-67,051) vs 2,966.5 (2,167-5,025) copies of amplifiable DNA per mL, P < .01. Median of 5 mL (interquartile range, 4.5-5) of pleural fluid supernatant was adequate for cfDNA testing.

INTERPRETATION

The diagnostic yield of pleural cfDNA NGS for oncogenic mutations in lung adenocarcinoma patients is comparable to tumor biopsies and higher than pleural cytology and plasma cfDNA. The pleural cfDNA can be longitudinally collected, can be readily incorporated in clinical workflow, and may decrease the need for additional biopsies.

Cytological Samples: An Asset for the Diagnosis and Therapeutic Management of Patients with Lung Cancer

BACKGROUND

Lung cancer has become the leading cause of cancer death for men and women. Most patients are diagnosed at an advanced stage when surgery is no longer a therapeutic option. At this stage, cytological samples are often the less invasive source for diagnosis and the determination of predictive markers. We assessed the ability of cytological samples to perform diagnosis, and to establish molecular profile and PD-L1 expression, which are essential for the therapeutic management of patients.

METHODS

We included 259 cytological samples with suspected tumor cells and assessed the ability to confirm the type of malignancy by immunocytochemistry. We summarized results of molecular testing by next generation sequencing (NGS) and PD-L1 expression from these samples. Finally, we analyzed the impact of these results in the patient management.

RESULTS

Among the 259 cytological samples, 189 concerned lung cancers. Of these, immunocytochemistry confirmed the diagnosis in 95%. Molecular testing by NGS was obtained in 93% of lung adenocarcinomas and non-small cell lung cancer. PD-L1 results were obtained in 75% of patients tested. The results obtained with cytological samples led to a therapeutic decision in 87% of patients.

CONCLUSION

Cytological samples are obtained by minimally invasive procedures and can provide enough material for the diagnosis and therapeutic management in lung cancer patients.

Diagnostic sensitivity of pleural fluid cytology in malignant pleural effusions: systematic review and meta-analysis

BACKGROUND

Pleural fluid cytology is an important diagnostic test used for the investigation of pleural effusions. There is considerable variability in the reported sensitivity for the diagnosis of malignant pleural effusions (MPE) in the literature.

OBJECTIVE

The purpose of this review is to determine the diagnostic sensitivity of pleural fluid cytology for MPE, both overall and by tumour type, to better inform the decision-making process when investigating pleural effusions.

DATA SOURCES

A literature search of EMBASE and MEDLINE was performed by four reviewers. Articles satisfying inclusion criteria were evaluated for bias using the QUADAS-2 tool.

DATA EXTRACTION

For quantitative analysis, we performed a metaanalysis using a binary random-effects model to determine pooled sensitivity. Subgroup analysis was performed based on primary cancer site and meta-regression by year of publication.

SYNTHESIS

Thirty-six studies with 6057 patients with MPE were included in the meta-analysis. The overall diagnostic sensitivity of pleural fluid cytology for MPE was 58.2% (95% CI 52.5% to 63.9%; range 20.5%-86.0%). There was substantial heterogeneity present among studies (I² 95.5%). For primary thoracic malignancies, sensitivity was highest in lung adenocarcinoma (83.6%; 95% CI 77.7% to 89.6%) and lowest in lung squamous cell carcinoma (24.2%; 95% CI 17.0% to 31.5%) and mesothelioma (28.9%; 95% CI 16.2% to 41.5%). For malignancies with extrathoracic origin, sensitivity was high for ovarian cancer (85.2%; 95% CI 74.2% to 96.1%) and modest for breast cancer (65.3%; 95% CI 49.8% to 80.8%).

CONCLUSIONS

Pleural fluid cytology has an overall sensitivity of 58.2% for the diagnosis of MPE. Clinicians should be aware of the high variability in diagnostic sensitivity by primary tumour type as well as the potential reasons for false-negative cytology results.PROSPERO registration numberCRD42021231473.

Malignant Pleural Effusion: Presentation, Diagnosis, and Management

Malignant pleural effusions are common in patients with cancer. Most malignant pleural effusions are secondary to metastases to the pleura, most often from lung or breast cancer. The presence of malignant effusion indicates advanced disease and poor survival; in lung cancer, the presence of malignant effusion upstages the cancer to stage 4. Usually presenting as a large, unilateral exudative effusion, most patients with malignant pleural effusion experience dyspnea. Prior to intervention, diagnosis of malignant pleural effusion and exclusion of infection should be made. Thoracic imaging is typically performed, with computed tomography considered by many to be the gold standard. Thoracic ultrasound is also useful, particularly if diaphragmatic or pleural thickening and nodularity can be identified. Cytology should then be obtained; this is typically done via pleural fluid aspiration or pleural biopsy. Treatment focuses on palliation and relief of symptoms. Numerous interventions are available, ranging from drainage with thoracentesis or indwelling pleural catheter to more definitive, invasive options such as pleurodesis. There is no clear best approach, and a patient-centered approach should be taken.

A retrospective analysis of serous effusions based on the newly proposed international system for reporting serous fluid cytopathology: a report of 3633 cases in an oncological center

Background

The International System for Reporting Serous Fluid Cytopathology (TIS) was recently proposed. We retrospectively applied TIS recommendations for reporting the cytological diagnosis of serous effusions and reported our experience.

Methods

All the serous effusions from January 2018 to September 2021 were retrieved from the database. Recategorization was performed using the TIS classification, the risk of malignancy (ROM) was calculated for each TIS category. In addition, on the basis of the original TIS classification, we further subdivided the TIS category IV (suspicious for malignancy, SFM) into 2 groups (IVa and IVb) according to cytological characteristics (quality and quantity) to explore the necessity of SFM subclassification. The performance evaluation was carried out using different samples (pleural, peritoneal and pericardial effusions) and preparation methods (conventional smears, liquid-based preparations and cell blocks).

Results

A total of 3633 cases were studied: 17 (0.5%) were diagnosed as ‘nondiagnostic’ (I, ND), 1100 (30.3%) as ‘negative for malignancy’ (II, NFM), 101 (2.8%) as ‘atypia of undetermined significance’ (III, AUS), 677 (18.6%) as ‘suspicious for malignancy’ (IV, SFM), and 1738 (47.8%) as ‘malignant’ (V, MAL). The ROMs for the categories were 38.5%, 28.6%, 52.1%, 99.4% and 100%, respectively. The ROM for SFM was significantly higher than that for AUS (P < 0.001), while the difference between the ROMs for IVa and IVb was insignificant. The sensitivity, negative predictive value (NPV) and diagnostic accuracy of liquid-based preparations were all superior to those of conventional smears and cell blocks in detecting abnormalities. Using the three preparation methods simultaneously had the highest sensitivity, NPV and diagnostic accuracy.

Conclusion

Serous effusion cytology has a high specificity and positive predictive value (PPV), and TIS is a user-friendly reporting system. Liquid-based preparations could improve the sensitivity of diagnosis, and it is best to use three different preparation methods simultaneously for serous effusion cytologic examination.

Management of Malignant Pleural Effusion: Where Are We Now?

Pleural malignancies are among the most common causes of pleural disease and form the basis of our daily pleural practice. There has been significant research and increase in both diagnostic and therapeutic management of malignant pleural diseases in the last decade. Good-quality data have led to a paradigm shift in the management options of pleural malignancies, and indwelling pleural catheter is now recommended and widely used as first-line intervention. Several trials compared different treatment modalities for pleural malignancies and continue to emphasize the need to reduce hospital length of stay and unnecessary pleural intervention, and the importance of patient choice in clinical decision making. This practical review aims to summarize the current knowledge for the management of pleural malignancies, and the understanding of the steps that we still have to climb to optimize management and reduce morbidity.

Reassessing the optimal volume for malignancy detection in serous fluid cytology

BACKGROUND

The international system for reporting serous fluid cytopathology (TIS) recommends submitting at least 50-75 mL of serous fluid to decrease false-negative results. However, prior studies did not agree on specific volume requirements or consensus adequacy criteria. Our study aims to assess whether fluid volume affects the adequacy rate and to assess the minimum volume necessary for optimal adequacy in pleural and peritoneal fluids.

METHODS

A total of 8530 serous fluid cytology cases were identified in the laboratory information system. Differences in mean fluid volume received in the laboratory were compared using an ANOVA Games-Howell test based on TIS category. The percentage of malignant diagnoses across the volume ranges of 0 to 5 mL, 5 to 10 mL, 10 to 25 mL, 25 to 50 mL, 50 to 75 mL, 75 to 100 mL, 100 to 150 mL, 150 to 250 mL, 250 to 500 mL, 500 to 2000 mL was compared in pleural and peritoneal fluids using a chi-square test, and a SiZer analysis was performed.

RESULTS

Mean fluid volume in inadequate, atypical, and negative cases was significantly lower compared to positive cases. A SiZer analysis showed a positive relationship between the malignancy fraction of pleural and peritoneal fluids and fluid volume. The percentage of malignant diagnoses in pleural and peritoneal fluid samples increased significantly up to a volume range of 75-100 mL.

CONCLUSIONS

There is a significant relationship between fluid volume, adequacy and detection of malignancy in serous effusion cytopathology. The malignancy fraction increases with larger fluid volumes but at least 75-100 mL of fluid should be submitted for optimal diagnosis of malignancy in pleural and peritoneal fluids.

Adequacy in pleural effusion: What is the minimum volume required for detection of malignant cells?

BACKGROUND

Adequacy criteria of pleural fluid volume for optimal reporting are contentious, and very little literature is available to date. This problem has not been addressed in the novel International System for Reporting Serous Fluid Cytology.

MATERIALS AND METHODS

A retrospective analysis was performed on 939 pleural fluid samples. Five volume bins were created: 0-9.9 ml, 10-19.9 ml, 20-34.9 ml, 35-69.9 ml, and > 70 ml and included 203, 222, 314, 174, and 26 samples, respectively. Volume bins were compared across various categories using a Chi-square test. A malignancy fraction was used to assess diagnostic accuracy. Descriptive statistics for categorical variables were done with median and interquartile range. A ROC curve was constructed to find if pleural fluid volume can be used to detect malignancy. A cut-off volume was found which can detect malignancy with optimum sensitivity.

RESULTS

The area under the Receiver Operating Characteristic curve showed that 55% of the time, the pleural volume can detect malignancy correctly. From the coordinates of the curve it was found that for a sensitivity of 81% and specificity of 40%, a cut-off volume of 13.5 ml of pleural fluid is sufficient to detect malignancy.

CONCLUSIONS

We recommend 13.5 ml as the minimum volume cut-off for a satisfactory pleural effusion cytology report. Below this volume, the false-negative rates increase, and the specimen may be deemed as limited for a conclusive diagnosis. As the volume rises above this threshold volume, the false negativity rate decreases but does not significantly improve malignant cells' detection.

Evaluation of pleural fluid cytology for the diagnosis of malignant pleural effusion: a retrospective cohort study

Background

Cytological examination of pleural fluid has good specificity, but imperfect sensitivity for the diagnosis of malignant pleural effusion (MPE). Published estimates of sensitivity vary and predictors of false negative cytology are not well established.

Aims

To estimate pleural fluid cytology sensitivity and identify risk factors for false negative cytology.

Methods

We conducted a retrospective cohort study of patients who had cytology testing of pleural fluid at Christchurch Hospital, New Zealand, from July 2017 to October 2019. Data on clinical and pleural fluid characteristics were collected. MPE was defined by positive pleural fluid cytology, tissue histology or multidisciplinary meeting consensus. We estimated sensitivity of the first pleural cytology assessment. We performed multivariate logistic regression to ascertain patient groups at greatest risk of false negative results.

Results

Initial pleural fluid cytology was diagnostic in 117 of 156 patients, providing a sensitivity (95% confidence interval (CI)) of 75.0% (67.4–81.6%). The sensitivity was 79.0% (66.8–88.3%) for lung cancer, 91.3% (72.0–98.9%) for breast cancer and 33.3% (95% CI 11.8–61.6%) for mesothelioma. Cloudy appearance of pleural fluid (odds ratio (OR) 0.12; 95% CI 0.03–0.54) and yellow/gold pleural fluid (OR 0.24; 95% CI 0.06–0.96) reduced the odds of false negative pleural cytology. Pleural thickening on computed tomography scan (OR 3.3; 95% CI 1.2–9.4) was a risk factor for false negative cytology.

Conclusion

Sensitivity of pleural fluid cytology was greatest in primary lung and breast cancer, and lowest in mesothelioma. Clinicians should be alert to false negative results when suspecting mesothelioma or if pleural thickening is present.

Application of the Indian academy of cytologists recommendations for reporting serous fluid cytopathology in routine reporting of ascitic fluid specimen and assessment of the risk of malignancy

Background:

A five-tiered reporting system for effusion fluid cytology has been published by the Indian Academy of Cytologists (IAC). Only a single study has evaluated the applicability of this system in routine reporting.

Aims:

We intend to evaluate the practical utility of this system in routine reporting of ascitic fluid cytology.

Materials And Methods:

Nine hundred and sixty-one cases of ascitic fluid cytology were included in this study. The clinical, radiological, cytomorphological, and follow-up data of these cases were reviewed. All cases were recategorized according to the proposed IAC system, and the risk of malignancy (ROM) for each category was estimated.

Results:

Age of the patients ranged from 1 to 92 years, and fluid volume ranged from 10 ml to 3 l. The number of cases included in each category and their respective ROM were as follows: category 1: 41, 21.42%; category 2: 805, 14.9%; category 3: 5, 33.3%; category 4: 31, 90%; and category 5:79, 96.4%.

Conclusions:

The new IAC guidelines for the serous fluid is representative, informative, and could be easily applied at our institutional level. We used the recommended diagnostic categories for reclassifying the ascitic fluid samples based on their cytosmear findings and conclude that the system has enormous utility at each level starting from the collection of fluid samples till the delivery of the report.

How much is enough: investigation of pleural fluid cytology findings related to sample volume

INTRODUCTION

Cytologic evaluation of pleural effusion samples plays an invaluable role in patient care. Despite this, only a few robust studies have investigated the optimal specimen volume for cytologic evaluation. It is not unusual for our laboratory to receive low-volume pleural effusion samples. Thus, as a part of ongoing quality assurance studies, we examined the performance of low-volume samples.

MATERIALS AND METHODS

All pleural effusion samples received during a 1-year period from January 1, 2020 to December 31, 2020 were reviewed. The case data collected included the clinical indications, diagnostic categorization, cell block performance, and adequacy notations. Follow-up data were also collected. The cases were placed into low-volume (≤10 mL, 11-25 mL, and 26-50 mL) and higher volume (>50 mL) groups for analysis.

RESULTS

A total of 226 samples were included in the present study. Of the 226 samples, 89 had a volume of ≤50 mL, including 32 with a very low volume of ≤10 mL. Significantly fewer positive cases were diagnosed in the ≤10-mL group relative to the >50-mL group (6.3% versus 27.7%) with significantly fewer cell blocks performed (15.6% versus 57.7%). However, only 7 of the ≤10 mL cases (21.9%) had been performed to rule out malignancy, significantly less than that for the >50 mL group (81 of 137; 59.1%). Additionally, none of the very-low-volume cases had an upgraded follow-up effusion sample.

CONCLUSIONS

The exact role of the sample volume is not entirely clear as there are many factors are at play beyond volume itself. Although larger specimen volumes might be more optimal for a number of reasons, malignancy can be diagnosed at even low sample volumes. Thus, there is value to examining all samples regardless of the volume received. Insertion of an adequacy comment might be prudent for low-volume cases, especially those with a high clinical concern for malignancy.

Malignant Pleural Effusions

Malignant pleural effusions have a significant burden on patients and the health care system. Diagnosis is typically via thoracentesis, although other times more invasive procedures are required. Management centers around relief of dyspnea and patient quality of life and can be done via serial thoracentesis, indwelling pleural catheter, or pleurodesis. This article focuses on the diagnosis and management of malignant pleural effusion.

The prevalence of tumour markers in malignant pleural effusions associated with primary pulmonary adenocarcinoma: a retrospective study

Background

Oncological treatment of primary pulmonary adenocarcinoma (AC) includes drugs targeting the pathways involving programmed death-ligand 1 (PD-L1), epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK). The aim of the study was to report the prevalence of these tumour markers in pleural fluid with cytology positive for pulmonary AC and the potential influence of volume pleural fluid tested.

Methods

We retrospectively reviewed all thoracenteses performed in a two-year period at our interventional unit at Department of Respiratory Medicine at Zealand University Hospital Naestved, Denmark. ALK and PD-L1 testing was done using immunohistochemistry and EGFR testing using next-generation sequencing. We included pleural fluid specimens containing malignant cells originating from primary pulmonary AC and with at least one tumour marker requested by the clinicians.

Results

When screening 927 pleural fluid specimens, we identified 57 in accordance with the inclusion criteria. PD-L1, ALK and EGFR were obtained in 35/55 (64%), 38/57 (67%) and 26/47 (55%), respectively. The prevalence did not increase when analysing volumes > 50 mL (p = 0.21–0.58)

Conclusion

Tumour markers in pleural fluid specimens containing cells from pulmonary AC can be demonstrated in more than half of the cases. Therefore, supplementary invasive procedures than thoracentesis could potentially await these analyses.

Application of the International System for Reporting Serous Fluid Cytopathology in routine reporting of pleural effusion and assessment of the risk of malignancy

INTRODUCTION

The International System for Reporting Serous Fluid Cytopathology (ISRSFC) was proposed by the International Academy of Cytology and the American Society of Cytopathology.

AIM OF THE STUDY

We have applied this system for reporting of pleural effusion cytology and report our experience.

MATERIALS AND METHODS

All the pleural effusions from January 2019 to June 2020 were retrieved from the database. All these cases were reviewed and recategorized according to the proposed system of 5 categories: non-diagnostic (ND), negative for malignancy (NFM), atypia of uncertain significance (AUS), suspicious for malignancy (SFM), and malignant (MAL). The risk of malignancy (ROM) for each category was evaluated.

RESULTS

A total of 939 cases were studied. The age of patients ranged from 2 to 88 years, and the volume of fluid ranged from 1 to 600 ml. There were 41 ND (4.37%), 697 NFM (74.23%), 44 AUS (4.69%), 27 SFM (2.88%), and 130 MAL (13.84%) cases. The ROM for the categories were found to be 87.5%, 51.61%, 88.23%, 87.5%, and 100% respectively.

CONCLUSIONS

The ISRSFC is a user-friendly system for use in reporting of pleural fluid. The criteria for defining the various categories need to be further elaborative and stricter for this system to be more effective. More studies are required for the estimation of the ROM for each category.

Cytohistological Correlation in Pleural Effusions Based on the International System for Reporting Serous Fluid Cytopathology

The International System for Reporting Serous Fluid Cytology (TIS) was recently developed. Given its novelty, most studies looking into the risk of malignancy (ROM) of serous effusion diagnostic categories were published before the development of TIS. We searched the database of our department for pleural effusions diagnosed in the last five years, excluding those without a corresponding pleural biopsy. Cases were reviewed and reclassified according to the TIS. A cytohistological correlation was performed. In total, 350 pleural effusion specimens with one or more corresponding pleural biopsies were included. After reclassification, 5 (1.43%) were nondiagnostic (ND), 253 (72.29%) were negative for malignancy (NFM), 7 (2.00%) had atypia of unknown significance (AUS), 14 (4.00%) were suspicious for malignancy (SFM), and 71 (20.57%) were malignant (MAL). Calculated ROM was 40% for ND, 20.16% for NFM, 42.86% for AUS, 78.57% for SFM, and 100% for MAL. Effusion cytology sensitivity and specificity were 60.29% and 98.56%, respectively. This is the first publication looking into the cytohistological correlation of a retrospective cohort of pleural effusions based on the TIS. We add to the body of data regarding the ROM for TIS categories, highlighting areas of potential future research.

Respiratory cytology in malignant lung disease - The thoracic oncologist's perspective

Respiratory cytology continues to play a central role in the diagnosis and staging of thoracic malignancy, although over time indications have changed. Historically, sputum cytology and endobronchial brushings and washings figured prominently, but with the advent of endobronchial and endoscopic ultrasound much greater emphasis is placed on fine needle aspirates from lymph nodes. The advent of targeted sequencing panels for genomic profiling to identify driver mutations and PD-L1 directed immunotherapy means that there is a need to extract increasing amounts of diagnostic and predictive information from ever smaller amounts of diagnostic material. Recent work has demonstrated that cytology samples are well suited to delivering the information required, but in order to understand the limitations of clinical and laboratory techniques, a close working relationship between pathologist and thoracic oncologist is needed to optimise sample procurement and utilisation.

Malignant Pleural Effusions-A Window Into Local Anti-Tumor T Cell Immunity?

The success of immunotherapy that targets inhibitory T cell receptors for the treatment of multiple cancers has seen the anti-tumor immune response re-emerge as a promising biomarker of response to therapy. Longitudinal characterization of T cells in the tumor microenvironment (TME) helps us understand how to promote effective anti-tumor immunity. However, serial analyses at the tumor site are rarely feasible in clinical practice. Malignant pleural effusions (MPE) associated with thoracic cancers are an abnormal accumulation of fluid in the pleural space that is routinely drained for patient symptom control. This fluid contains tumor cells and immune cells, including lymphocytes, macrophages and dendritic cells, providing a window into the local tumor microenvironment. Recurrent MPE is common, and provides an opportunity for longitudinal analysis of the tumor site in a clinical setting. Here, we review the phenotype of MPE-derived T cells, comparing them to tumor and blood T cells. We discuss the benefits and limitations of their use as potential dynamic biomarkers of response to therapy.

The International System for Reporting Serous Fluid Cytopathology: How to Incorporate Molecular Data in Cytopathology Reports

Serous effusion cytology is widely employed in the initial evaluation of the etiology of effusions with a high diagnostic sensitivity. To standardize practices, The International System for Reporting Serous Fluid Cytology (TIS) was developed following best international practices, the most up-to-date literature, and expert consensus. In the context of this system, ancillary techniques play an important role. Besides defining basic principles in laboratory specimen handling, adequacy criteria, and a standardized reporting terminology with five diagnostic categories, TIS provides an actionable framework for using immunohistochemical and molecular testing in effusion samples, namely, in atypical, suspicious of malignant samples. For diagnostic purposes, these tests may be employed to distinguish between a primary and secondary neoplasm, to confirm a diagnosis of malignant mesothelioma vs. reactive mesothelial hyperplasia, and to correctly classify and determine the primary location of a metastasis. Theranostic molecular tests may also be used for these samples to evaluate potential therapeutic targets. Pathologists play a central role in guiding this process by determining adequacy and selecting appropriate ancillary tests. The activity in this area of research should increase in the near future as new therapeutic targets are discovered and new drugs enter the clinical practice.

Root cause analysis of indeterminate diagnoses in serous fluids cytopathology

INTRODUCTION

The International System for Reporting Serous Fluid Cytopathology proposed five diagnostic categories: Nondiagnostic (ND), Negative for Malignancy (NFM), Atypia of Undetermined Significance (AUS), Suspicious for Malignancy (SFM) and Malignant (MAL) (Primary or Metastatic). The indeterminate (AUS/SFM) categories are challenging for management. The goal of this study is to reveal the root causes contributing to indeterminate diagnoses (ID).

MATERIALS AND METHODS

We searched our archives between 1 January 2017 and 30 June 2019, and performed a root cause analysis (RCA) using the "5 whys" method to determine the contributing factors of ID.

RESULTS

Nine hundred eleven specimens were evaluated and diagnosed: ND (9, 1%), NFM (667, 73.2%), AUS (51, 5.6%), SFM (27, 3%) and MAL (157, 17.2%). More than one factor contributed to 38/78 ID. Low volume (<50 cc), and low cellularity were identified in 31 and 51 cases, respectively. Three cases were simply deferred to concurrent biopsy. Eleven cases were called atypical, favor reactive mesothelium despite confirmatory IHC. Atypical lymphoid population was reported in seven cases. Cellblocks (CB) were low in cellularity despite volume >1000 mL in 13 cases. Two mesotheliomas were underdiagnosed as suspicious.

CONCLUSIONS

Low cellularity and low volume were the most common contributing factors, highlighting the importance of adequate sample collection. Adequate volume specimens with low cellularity may benefit from a close inspection and a second CB. Some IDs can be switched to NFM or MAL with careful consideration of clinical, radiologic findings and ancillary testing, and concurrent surgical pathology correlation when available.

Contemporary Approach to the Diagnosis of Malignant Pleural Effusion

Advanced malignancy is a prevalent cause of exudative pleural effusion. The management of malignant pleural effusion (MPE) has been the subject of several recent randomized controlled trials and excellent reviews. Less attention has been focused on another controversial and challenging aspect of MPE: establishing the diagnosis. Before selecting the optimal management strategy, the presence of an MPE must first be correctly identified with an emphasis on minimizing invasiveness and discomfort in a patient with late-stage cancer. The aim of the present review is to summarize the current knowledge about MPE diagnostics and to propose an algorithm for the diagnosis of MPE in established or suspected malignancy.

Malignant Pleural Effusion: Diagnosis and Management

Symptomatic malignant pleural effusion is a common clinical problem. This condition is associated with very high mortality, with life expectancy ranging from 3 to 12 months. Studies are contributing evidence on an increasing number of therapeutic options (therapeutic thoracentesis, thoracoscopic pleurodesis or thoracic drainage, indwelling pleural catheter, surgery, or a combination of these therapies). Despite the availability of therapies, the management of malignant pleural effusion is challenging and is mainly focused on the relief of symptoms. The therapy to be administered needs to be designed on a case-by-case basis considering patient's preferences, life expectancy, tumour type, presence of a trapped lung, resources available, and experience of the treating team. At present, the management of malignant pleural effusion has evolved towards less invasive approaches based on ambulatory care. This approach spares the patient the discomfort caused by more invasive interventions and reduces the economic burden of the disease. A review was performed of the diagnosis and the different approaches to the management of malignant pleural effusion, with special emphasis on their indications, usefulness, cost-effectiveness, and complications. Further research is needed to shed light on the current matters of controversy and help establish a standardized, more effective management of this clinical problem.

The international system for reporting serous fluid cytopathology-diagnostic categories and clinical management

INTRODUCTION

Effusions can develop inside serous cavities in several pathologic states, both neoplastic and non-neoplastic. They are easy to drain and can provide useful diagnostic information. However, the reported diagnostic efficacy of these specimens has not been uniform across different laboratories. To standardize practices, the international system for reporting serous fluid cytology (TIS) was developed in accordance with the best international practices, the most up-to-date reported data, and expert consensus.

RESULTS

TIS has set the basic principles for laboratory handling of serous effusion specimens, defined the adequacy criteria, and set a standardized reporting terminology with well-defined criteria for each diagnostic category. These include nondiagnostic, negative for malignancy, atypia of undetermined significance, suspicious for malignancy, and malignant. Each can provide useful inherent information for appropriate clinical management and follow-up, with a defined expected diagnostic category incidence and risk of malignancy.

CONCLUSIONS

TIS applies to serous fluids collected from the pleura, peritoneal, and pericardial cavities. Using TIS, indeterminate categories are presented as either preliminary or as options of last resource. TIS has emphasized the role of ancillary tests in arriving at the correct interpretation within each category. It also has emphasized the importance of a malignant diagnosis as a definitive diagnosis, comparable to histologic examinations. Because of the well-documented outcomes in the adoption of uniform cytology terminology for other organ systems, we recommend the use of the upcoming TIS and believe its use will be paramount to improving the diagnostic yield in this area of cytology.

Collection and Handling of Thoracic Small Biopsy and Cytology Specimens for Ancillary Studies: Guideline From the College of American Pathologists in Collaboration With the American College of Chest Physicians, Association for Molecular Pathology, American Society of Cytopathology, American Thoracic Society, Pulmonary Pathology Society, Papanicolaou Society of Cytopathology, Society of Interventional Radiology, and Society of Thoracic Radiology

CONTEXT.—

The need for appropriate specimen use for ancillary testing has become more commonplace in the practice of pathology. This, coupled with improvements in technology, often provides less invasive methods of testing, but presents new challenges to appropriate specimen collection and handling of these small specimens, including thoracic small biopsy and cytology samples.

OBJECTIVE.—

To develop a clinical practice guideline including recommendations on how to obtain, handle, and process thoracic small biopsy and cytology tissue specimens for diagnostic testing and ancillary studies.

METHODS.—

The College of American Pathologists convened an expert panel to perform a systematic review of the literature and develop recommendations. Core needle biopsy, touch preparation, fine-needle aspiration, and effusion specimens with thoracic diseases including malignancy, granulomatous process/sarcoidosis, and infection (eg, tuberculosis) were deemed within scope. Ancillary studies included immunohistochemistry and immunocytochemistry, fluorescence in situ hybridization, mutational analysis, flow cytometry, cytogenetics, and microbiologic studies routinely performed in the clinical pathology laboratory. The use of rapid on-site evaluation was also covered.

RESULTS.—

Sixteen guideline statements were developed to assist clinicians and pathologists in collecting and processing thoracic small biopsy and cytology tissue samples.

CONCLUSIONS.—

Based on the systematic review and expert panel consensus, thoracic small specimens can be handled and processed to perform downstream testing (eg, molecular markers, immunohistochemical biomarkers), core needle and fine-needle techniques can provide appropriate cytologic and histologic specimens for ancillary studies, and rapid on-site cytologic evaluation remains helpful in appropriate triage, handling, and processing of specimens.

Number of mesothelial cells as a measure of adequacy criteria for pleural effusions: A multi-institutional study

BACKGROUND

The development of a terminology system is essential to allow uniformity in reporting serous fluid specimens. An important topic to cover is the issue of specimen adequacy. In the present study, we aimed to evaluate whether there is a correlation between number of mesothelial cells and overall improved sensitivity and adequacy control of tests.

METHODS

Cases of negative pleural fluids with concomitant positive pleural biopsies were selected from two referral institutions, with observation of the number of mesothelial cells in 10 high-power fields, comparing the results with a control group (cases with negative biopsies, ie, true negatives). Comparisons were conducted using the nonparametric Mann-Whitney U test. Data were analysed for sensitivity and specificity derived from the receiver operating characteristics curve. For the choice of an optimal cut-off of mesothelial cells, receiver operating curve analysis was constructed and the Youden index was calculated.

RESULTS

A total of 112 pleural effusions with paired pleural biopsies were studied. There was no difference in distributions of the number of mesothelial cells between cases with a positive biopsy (false negatives) and the control group (median = 39 vs median = 30, respectively, P-value = .974). However, simple logistic regression found a cut-off of 750 cells per 10 high-power fields as an optimal number for improved sensitivity (72.7%), with fair discriminatory power.

CONCLUSIONS

Enumeration of mesothelial cells may improve the sensitivity of the cytological diagnosis of malignant pleural effusion, serving as an internal quality control for the test's overall accuracy.

Yield of Malignant Pleural Effusion for Detection of Oncogenic Driver Mutations in Lung Adenocarcinoma

BACKGROUND

Pleural fluid can be used to assess targetable mutations in patients with lung adenocarcinoma. The primary objective of this study was to assess the yield of pleural fluid cytology for targetable oncogenic mutations (EGFR, KRAS, BRAF, ALK, and ROS1 gene rearrangements). We also assessed pleural fluid volume necessary for molecular testing.

METHODS

Retrospective review was performed of 134 consecutive patients with lung adenocarcinoma associated malignant pleural effusions. EGFR and KRAS testing was done using PCR amplification followed by DNA sequencing, or next generation sequencing in more recent cases that included BRAF assessment. Fluorescence in situ hybridization employing break-apart probes was used to test for ALK and ROS1 rearrangements.

RESULTS

Mutation analysis on pleural fluid cell-block was performed on 56 patients. It was adequate for complete analysis ordered including EGFR, KRAS, BRAF, ALK, and ROS1 rearrangements on 40 (71.4%) samples. For individual mutations, EGFR testing was possible in 38 of 49 (77.6%); KRAS 22 of 28 (78.6%); BRAF 10 of 13 (76.9%), ALK gene rearrangement 42 of 51 (82.4%) and ROS1 gene rearrangement in 21 of 28 (75%) pleural fluid specimens. The analysis was satisfactory in 13 of 19 (68.4%) samples with ≤100 mL versus 27 of 37 (72.9%) with >100 mL of fluid tested (P-value=0.7).

CONCLUSION

Genetic mutation analysis can be performed on malignant pleural effusions secondary to lung adenocarcinoma, independent of fluid volume.

A 2-year retrospective study on pleural effusions: A cancer centre experience

BACKGROUND

Cytopathological examination of pleural effusions is a fast and minimally invasive method for verification of the presence of neoplastic cells. We report our 2-year experience using a categorised diagnostic system and reporting risks of malignancy (ROMs) for each defined category.

METHODS

Cytological reports of patients between November 2016 and October 2018 were collected, with results primarily classified into a five-tiered classification scheme. Immunohistochemistry markers used in cytology and their results were also recorded. Final agreement to histology and overall test performance was calculated for cases with available concomitant (up to 3 months) pleural biopsies.

RESULTS

A total of 519 samples from 385 patients were collected, being 29 (5.6%) classified as non-diagnostic, 291 (56%) as negative, 28 (5.4%) as atypical, 30 (5.8%) as suspicious and 141 (27.2%) as positive. Most requested markers were calretinin, TTF1, Ber-EP4 and Gata-3, being conclusive in 45 (76.3%) cases. Total cyto-histological agreement was achieved in 49 (80.3%) specimens, with an overall sensitivity and specificity of 69.4% and 93.3%, respectively. Positive predictive value was 96.2% and negative predictive value was of 56%. ROM for each diagnostic category was 50% for non-diagnostic, 44% for negative, 50% for atypical, 83.3% for suspicious and 96.2% for positive.

CONCLUSIONS

Our 2-year retrospective study has shown a high specificity and positive predictive value for pleural cytology. The use of a five-tiered system has also shown to be highly effective, with a concordantly progressive higher ROM for the assigned diagnostic categories.

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.

Baseline predictors of negative and incomplete pleural cytology in patients with suspected pleural malignancy - Data supporting 'Direct to LAT' in selected groups

OBJECTIVES

Negative effusion cytology is more common in certain forms of Malignant Pleural Effusion (MPE) and results in pathway delay. Local Anaesthetic Thoracoscopy (LAT) is extremely sensitive and safe but cannot be offered to all. A stratified pathway, including 'Direct to LAT' in selected cases could enhance patient experience but requires reliable baseline predictors of unhelpful cytology, including both negative (no malignant cells) and incomplete results (malignant cells identified but predictive markers failed), since pleural biopsies will be required in the latter for optimal management. This retrospective analysis of a prospective multi-centre study, sought to identify baseline features for pathway rationalization.

MATERIALS AND METHODS

363/638 (57%) of patients recruited to the DIAPHRAGM study (ISRCTN10079972) were included. Prospective data, including final diagnoses, asbestos exposure and fluid cytology results were supplemented by retrospective Computed Tomography (CT) and predictive marker reports. Independent predictors of negative and incomplete cytology were determined by multivariable logistic regression. Contingency tables were used to assess diagnostic value of cytology in associated phenotypes.

RESULTS

238/363 (66%) patients were diagnosed with MPE (18 tumour types). Fluid cytology was negative in 151/238 (63%) and independently associated with asbestos-exposure (Odds Ratio (OR) 5.34) and a malignant CT (OR 2.25). When both features were recorded the sensitivity and negative predictive value of fluid cytology were 19% (95% CI 11-30%) and 9% (95% CI 4-20%)), respectively. Cytology was incomplete in 34/238 (14%), i.e. 47% of positive cytology cases) but was not associated with any baseline feature. ORs for incomplete cytology in Ovarian, Breast, Renal and Lung Cancer were 83, 22, 21 and 9, respectively.

CONCLUSION

Negative cytology is extremely likely in patients with asbestos exposure and a malignant CT report. A 'Direct-to-LAT' approach may be appropriate in this setting. No baseline predictors of incomplete cytology were identified.

Investigating unilateral pleural effusions: the role of cytology

The vast majority of undiagnosed unilateral pleural effusions have fluid sent for cytological analysis. Despite widespread use, there is uncertainty about its sensitivity to diagnose malignant pleural effusions (MPEs). Our aim was to ascertain the utility of cytology using a large prospective cohort.Consecutive patients presenting with an undiagnosed unilateral pleural effusion were recruited to this UK-based study. All had pleural fluid sent for cytological analysis. Cytological sensitivity was based on the final diagnosis at 12 months, confirmed by two consultants.Over 8 years, 921 patients were recruited, of which 515 had a MPE. Overall sensitivity of fluid cytology to diagnose malignancy was 46% (95% CI 42-58%). There was variation in sensitivity depending on cancer primary, with mesothelioma (6%) and haematological malignancies (40%) being significantly lower than adenocarcinomas (79%). MPEs secondary to ovarian cancer had high pick-up rates (95%). In asbestos-exposed males with exudative effusions, the risk of MPE was 60%, but cytological sensitivity was 11%.This is the largest prospective study of pleural fluid cytology and informs discussions with patients about the likely requirement for investigations following thoracentesis. In patients presenting with a clinical suspicion of mesothelioma, cytological sensitivity is low, so more definitive investigations could be performed sooner.

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.

Malignant Pleural Effusion: From Diagnostics to Therapeutics

Malignant pleural effusion is a common complication of cancer and denotes a poor prognosis. It usually presents with dyspnea and a unilateral large pleural effusion. Thoracic computed tomography scans and ultrasound are helpful in distinguishing malignant from benign effusions. Pleural fluid cytology is diagnostic in about 60% of cases. In cytology-negative disease, pleural biopsies are helpful. Current management is palliative. Previously, first-line treatment for recurrent symptomatic malignant pleural effusion was chest drain insertion and talc pleurodesis, with indwelling pleural catheter insertion reserved for patients with trapped lung or failed talc pleurodesis. However, catheter insertion is an increasingly acceptable first-line treatment.

The minimum volume of pleural fluid required to diagnose malignant pleural effusion: A retrospective study

BACKGROUND

Pleural fluid cytology is a quick and accurate method to diagnose malignant pleural effusions. The optimal volume of fluid for cytological analysis has not yet been identified, and clinical recommendation based on some published clinical experiences has been to send large volumes of fluid for cytological analysis. A quality improvement initiative at our institution was conducted to determine the volume of fluid sufficient for a diagnosis of malignant pleural effusion.

MATERIALS AND METHODS

The study was approved by the Institutional Review Board. All pleural fluid specimens that were divided into three volumes (25 mL, 50 mL, and 150 mL) and sent for cytological examination were reviewed.

RESULTS

A total of 74 samples from 60 individual patients were evaluable. Thirty-six patients (60%) had a previous diagnosis of malignancy. Of the 74 specimens, 26 (35.1%) were positive for malignancy. The detection rate for malignant pleural effusion by cytology for 25 mL, 50 mL, and 150 mL were 88.5%, 96.2%, and 100.0%, respectively (P = 0.16). Two specimens that were negative in the 25 mL samples turned out to be positive in the 50 mL and 150 mL samples. One specimen was negative in the 25 mL and 50 mL samples but positive in the 150 mL sample.

CONCLUSIONS

Our study did not show any statistically significant difference in the detection of malignant effusion in the 25 mL, 50 mL, and 150 mL group.

Lipidomic Profiling of Lung Pleural Effusion Identifies Unique Metabotype for EGFR Mutants in Non-Small Cell Lung Cancer

Cytology and histology forms the cornerstone for the diagnosis of non-small cell lung cancer (NSCLC) but obtaining sufficient tumour cells or tissue biopsies for these tests remains a challenge. We investigate the lipidome of lung pleural effusion (PE) for unique metabolic signatures to discriminate benign versus malignant PE and EGFR versus non-EGFR malignant subgroups to identify novel diagnostic markers that is independent of tumour cell availability. Using liquid chromatography mass spectrometry, we profiled the lipidomes of the PE of 30 benign and 41 malignant cases with or without EGFR mutation. Unsupervised principal component analysis revealed distinctive differences between the lipidomes of benign and malignant PE as well as between EGFR mutants and non-EGFR mutants. Docosapentaenoic acid and Docosahexaenoic acid gave superior sensitivity and specificity for detecting NSCLC when used singly. Additionally, several 20- and 22- carbon polyunsaturated fatty acids and phospholipid species were significantly elevated in the EGFR mutants compared to non-EGFR mutants. A 7-lipid panel showed great promise in the stratification of EGFR from non-EGFR malignant PE. Our data revealed novel lipid candidate markers in the non-cellular fraction of PE that holds potential to aid the diagnosis of benign, EGFR mutation positive and negative NSCLC.

Advances in pleural diseases: what is the future for medical thoracoscopy?

PURPOSE OF REVIEW

Medical thoracoscopy provides the physician a window into the pleural space. The procedure allows biopsy of the parietal pleura under direct visualization with good accuracy. In addition, it achieves therapeutic goals of fluid drainage, guided chest tube placement, and pleurodesis.

RECENT FINDINGS

Comparable diagnostic yield is achieved with the flexi-rigid pleuroscope even though pleural biopsies are smaller using the flexible forceps as compared to rigid thoracoscopy. Flexi-rigid pleuroscopy is extremely well tolerated and can be performed safely as an outpatient procedure. Biopsy quality can be further enhanced with accessories that are compatible with the flex-rigid pleuroscope such as the insulated tip knife and cryoprobe.

SUMMARY

With more sensitive tools to image the pleura such as contrast-enhanced computed tomography, MRI, ultrasonography, PET, increased yield with image-guided biopsy as well as advances in cytopathology, what lies in the future for medical thoracoscopy remains to be seen. However, it is the authors' opinion that medical thoracoscopy will evolve with time, complement novel techniques, and continue to play a pivotal role in the evaluation of pleuropulmonary diseases.

A Minimum Volume of More Than 60 mL Is Necessary for Adequate Cytologic Diagnosis of Malignant Pericardial Effusions

OBJECTIVES

This study aims to determine the minimum pericardial fluid volume necessary for adequate cytologic diagnosis.

METHODS

We identified 480 pericardiocentesis specimens, divided them by volume into six bins, and calculated the malignancy fraction (percentage of malignant diagnoses) for each bin. We then combined bins at various cutoffs to determine a minimum threshold volume and evaluated their sensitivity.

RESULTS

The malignancy fraction increased from 6.5% for specimens 10 mL or less to 20.7% for more than 600 mL (P = .03). While the cumulative malignancy fraction was 18.1% above a cutoff of 60 mL, it was 10.6% below this threshold (P = .03). The sensitivity of cytology compared with pericardial biopsy was 70.0% for 60 mL or less and 91.1% for more than 60 mL (P = .14).

CONCLUSIONS

Small-volume pericardiocentesis specimens detect fewer malignancies and have inferior sensitivity compared with pericardial biopsy. A volume of more than 60 mL should be submitted to cytology to ensure adequate diagnosis of pericardial fluids.

A specimen volume of ≥80 mL improves cytologic sensitivity for malignant ascites: a retrospective analysis of 2665 cases

INTRODUCTION

Although paracentesis simultaneously allows cytologic evaluation of peritoneal fluid and symptomatic relief, its utility is limited by a paltry 50% to 60% sensitivity for malignancy. Specimen volume has recently been shown to affect cytologic diagnosis in other body fluids, but its role has never been examined in ascites. This study evaluates how specimen volume impacts cytologic diagnosis of malignant ascites.

MATERIALS AND METHODS

We identified 2665 consecutive paracentesis specimens with documented numeric volumes collected at our institution between 1994 and 2013. We separated the cases into 10 bins of roughly equivalent sample size and compared the percentage of cases that received malignant diagnoses across each cutoff volume. When follow-up pathology was available, we also compared the sensitivity of cytology with the gold standard of surgical pathology.

RESULTS

The peritoneal fluids had a mean volume of 760.2 mL (range: 1-10,000). Just 11.3% of specimens with volumes <80 mL were diagnosed as malignant, while 20.1% were malignant at volumes ≥80 mL (P < 0.001, OR = 0.51, 95% CI = 0.39-0.64). Lower volume specimens also had more indeterminate and nondiagnostic results. Cytologic sensitivity increased from 56.7% for specimens <80 mL to 75.4% for volumes ≥80 mL (P = 0.03, OR = 0.43, 95% CI = 0.19-0.94).

CONCLUSIONS

A specimen volume of ≥80 mL is associated with increased cytologic sensitivity for malignant ascites and a higher rate of malignant diagnoses. The disparate sensitivity at lower volumes likely stems from inadequate sampling of larger specimens. Although fluids should not be summarily rejected based on volume, a specimen volume of ≥80 mL minimizes the influence of specimen size on diagnostic adequacy in paracentesis specimens.

Assessment of a panel of tumor markers for the differential diagnosis of benign and malignant effusions by well-based reverse phase protein array

Background

The differential diagnosis of benign and malignant effusion is often hampered by low cell content or insufficiently preserved tumor cells. In this study, we evaluated the combined diagnostic value of six tumor markers measured by well-based reverse-phase protein array (RPPA) for diagnosis of malignant effusion.

Methods

A total of 114 patients (46 with malignant effusions, 32 with probable malignant effusions, and 36 with benign effusions) were enrolled. Expressional levels of MUC1, EMA, Pan-CK, HSP90, TGF-β and CA125 were determined by well-based RPPA.

Results

Median relative expression of MUC1, Pan-CK and EMA were significantly higher in malignant effusion than those in probable malignant or benign (p < 0.001, p = 0.003, p < 0.001, respectively), whereas the level of TGF-β in malignant effusions were significantly lower than that in the other groups (p = 0.005). For predicting malignancy, EMA presented the best areas under the curve of 0.728 followed by MUC1 of 0.701. The sensitivity of 52.0% for MUC1 and 48.0% for EMA were not better than cytology. However, sensitivity, negative predictive value, and accuracy of the tumor marker panel were better than cytology by 14.7%, 7.5%, and 6.1%, respectively.

Conclusions

Tumor marker panel measured by well-based RPPA showed values in the differential diagnosis between benign and malignant effusions. Further large scale studies need to be performed to evaluate the utility of this panel of markers.

Virtual slides

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Electronic supplementary material

The online version of this article (doi:10.1186/s13000-015-0290-4) contains supplementary material, which is available to authorized users.

[Pleural effusion: diagnosis and management]

Pleural effusion management is a common clinical situation associated with numerous pulmonary, pleural or extra-pulmonary diseases. A systematic approach is needed to enable a rapid diagnosis and an appropriate treatment. Pleural fluid analysis is the first step to perform which allows a presumptive diagnosis in most cases. Otherwise, further analysis of the pleural fluid or thoracic imaging or pleural biopsy may be necessary. This review aims at highlighting the important elements of the work-up required by a pleural effusion.

A minimum fluid volume of 75 mL is needed to ensure adequacy in a pleural effusion: a retrospective analysis of 2540 cases

BACKGROUND

No consensus exists regarding minimum fluid volume for adequacy of benign pleural effusion specimens. Although any volume is acceptable if cytologic findings are malignant, the distinction between the absence of disease and false-negativity is not straightforward in low-volume specimens. Recent literature has offered conflicting results regarding what minimum volume is necessary. Moreover, no studies to date have evaluated this issue across a large series of specimens with a wide distribution of volumes. The objective of the current study was to determine the minimum volume of pleural fluid necessary for optimal cytopathological diagnosis.

METHODS

The authors identified 2540 pleural fluid specimens received between January 2000 and December 2009 and retrospectively reviewed their diagnoses and characteristics. Because of the large range of volumes (1 mL-6500 mL), the cases were binned into 9 groups of roughly equivalent sample sizes. The malignancy fractions (percentage of cases with malignant diagnoses) were compared for each group.

RESULTS

The current study specimens had a median volume of 200 mL and an overall malignancy fraction of 20.1%. The malignancy fraction increased from 10.1% (95% confidence interval, 8.1%-12.1%) for volumes < 5 mL to 23.3% (95% confidence interval, 20.0%-25.8%) for volumes between 50 mL and 75 mL (P = .009). Specimens with volumes ≥ 75 mL had malignancy fractions independent of volume. In addition, ratios of benign or malignant diagnoses versus nondiagnostic and atypical results continued to increase with volume.

CONCLUSIONS

A fluid volume of ≥ 75 mL is required to eliminate the influence of specimen size on diagnostic adequacy. Although larger volumes do not appear to impact malignancy fraction, they do correlate with decreased nondiagnostic and atypical results.

Molecular characterization of scant lung tumor cells using iron-oxide nanoparticles and micro-nuclear magnetic resonance

Advances in nanotechnology and microfluidics are enabling the analysis of small amounts of human cells. We tested whether recently developed micro-nuclear magnetic resonance (μNMR) technology could be leveraged for diagnosing pulmonary malignancy using fine needle aspirate (FNA) of primary lesions and/or peripheral blood samples. We enrolled a cohort of 35 patients referred for CT biopsy of primary pulmonary nodules, liver or adrenal masses and concurrently obtained FNA and peripheral blood samples. FNA sampling yielded sufficient material for μNMR analysis in 91% of cases and had a sensitivity and specificity of 91.6% and 100% respectively. Interestingly, among blood samples with positive circulating tumor cells (CTC), μNMR analysis of each patient's peripheral blood led to similar diagnosis (malignant vs benign) and differential diagnosis (lung malignancy subtype) in 100% and 90% (18/20) of samples, respectively. μNMR appears to be a valuable, non-invasive adjunct in the diagnosis of lung cancer.

FROM THE CLINICAL EDITOR

The authors of this study established that recently developed micro-nuclear magnetic resonance (μNMR) technology can be leveraged for diagnosing pulmonary malignancy using fine needle aspirate (FNA) of primary lesions and/or peripheral blood samples derived from 35 patients, suggesting practical clinical applicability of this technique.

Establishing the diagnosis of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Lung cancer is usually suspected in individuals who have an abnormal chest radiograph or have symptoms caused by either local or systemic effects of the tumor. The method of diagnosis of lung cancer depends on the type of lung cancer (small cell lung cancer or non-small cell lung cancer [NSCLC]), the size and location of the primary tumor, the presence of metastasis, and the overall clinical status of the patient. The objective of this study was to determine the test performance characteristics of various modalities for the diagnosis of suspected lung cancer.

METHODS

To update previous recommendations on techniques available for the initial diagnosis of lung cancer, a systematic search of the MEDLINE, Healthstar, and Cochrane Library databases covering material to July 2011 and print bibliographies was performed to identify studies comparing the results of sputum cytology, conventional bronchoscopy, flexible bronchoscopy (FB), electromagnetic navigation (EMN) bronchoscopy, radial endobronchial ultrasound (R-EBUS)-guided lung biopsy, transthoracic needle aspiration (TTNA) or biopsy, pleural fluid cytology, and pleural biopsy with histologic reference standard diagnoses among at least 50 patients with suspected lung cancer. Recommendations were developed by the writing committee, graded by a standardized method (see the article "Methodology for Development of Guidelines for Lung Cancer" in this guideline), and reviewed by all members of the Lung Cancer Guideline Panel prior to approval by the Thoracic Oncology NetWork, the Guidelines Oversight Committee, and the Board of Regents of the American College of Chest Physicians.

RESULTS

Sputum cytology is an acceptable method of establishing the diagnosis of lung cancer, with a pooled sensitivity rate of 66% and a specificity rate of 99%. However, the sensitivity of sputum cytology varies according to the location of the lung cancer. For central, endobronchial lesions, the overall sensitivity of FB for diagnosing lung cancer is 88%. The diagnostic yield of bronchoscopy decreases for peripheral lesions. Peripheral lesions &lt; 2 or &gt; 2 cm in diameter showed a sensitivity of 34% and 63%, respectively. R-EBUS and EMN are emerging technologies for the diagnosis of peripheral lung cancer, with diagnostic yields of 73% and 71%, respectively. The pooled sensitivity of TTNA for the diagnosis of lung cancer was 90%. A trend toward lower sensitivity was noted for lesions &lt; 2 cm in diameter. TTNA is associated with a higher rate of pneumothorax compared with bronchoscopic procedures. In a patient with a malignant pleural effusion, pleural fluid cytology is reported to have a mean sensitivity of about 72%. A definitive diagnosis of metastatic disease to the pleural space can be estalished with a pleural biopsy. The diagnostic yield for closed pleural biopsy ranges from 38% to 47% and from 75% to 88% for image-guided closed biopsy. Thoracoscopic biopsy of the pleura carries the highest diagnostic yield, 95% to 97%. The accuracy in differentiating between small cell and non-small cell cytology for the various diagnostic modalities was 98%, with individual studies ranging from 94% to 100%. The average false-positive and false-negative rates were 9% and 2%, respectively. Although the distinction between small cell and NSCLC by cytology appears to be accurate, NSCLCs are clinically, pathologically, and molecularly heterogeneous tumors. In the past decade, clinical trials have shown us that NSCLCs respond to different therapeutic agents based on histologic phenotypes and molecular characteristics. The physician performing diagnostic procedures on a patient suspected of having lung cancer must ensure that adequate tissue is acquired to perform accurate histologic and molecular characterization of NSCLCs.

CONCLUSIONS

The sensitivity of bronchoscopy is high for endobronchial disease and poor for peripheral lesions &lt; 2 cm in diameter. The sensitivity of TTNA is excellent for malignant disease, but TTNA has a higher rate of pneumothorax than do bronchoscopic modalities. R-EBUS and EMN bronchoscopy show potential for increasing the diagnostic yield of FB for peripheral lung cancers. Thoracoscopic biopsy of the pleura has the highest diagnostic yield for diagnosis of metastatic pleural effusion in a patient with lung cancer. Adequate tissue acquisition for histologic and molecular characterization of NSCLCs is paramount.

The role of vascular endothelial growth factor in the pathogenesis, diagnosis and treatment of malignant pleural effusion

Malignant pleural effusions (MPEs) are a significant source of cancer-related morbidity. Over 150,000 patients in the United States suffer from breathlessness and diminished quality of life due to MPE each year. Current management strategies are of mostly palliative value and focus on symptom control; they do not address the pathobiology of the effusion, nor do they improve survival. Further elucidation of the pathophysiological mechanisms, coupled with the development of novel treatments such as intrapleural chemotherapeutics targeting this process, has the potential to greatly improve the efficacy of our current management options. Vascular endothelial growth factor-A (VEGF-A) has been implicated as a critical cytokine in the formation of malignant pleural effusions. Elevated levels of VEGF produced by tumor cells, mesothelial cells, and infiltrating immune cells result in increased vascular permeability, cancer cell transmigration, and angiogenesis. Therefore antiangiogenic therapies such as Bevacizumab, a monoclonal antibody targeting VEGF-A, may have a potential role in the management of malignant pleural effusions. Herein we review the pathogenesis and potential treatment strategies of malignant pleural effusions, with a focus on angiogenesis and antiangiogenic therapeutics.

Transoesophageal endoscopic ultrasound-guided fine-needle aspiration of pleural effusion for the staging of non-small cell lung cancer

OBJECTIVES

The efficacy of endoscopic ultrasound (EUS) for evaluating mediastinal adenopathy in lung cancer is nowadays proven. However, its accuracy for detection of malignant pleural effusion per se has not been yet investigated. Herein we report our experience with EUS for detecting pleural effusion during the staging procedure of non-small cell lung cancer (NSCLC) patients.

METHODS

Between January 2009 and December 2011, we performed endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) on 92 selected NSCLC patients to evaluate the T and N factors and to acquire bioptic material and when this was detected, to sample the pleural effusion.

RESULTS

In 10 patients (8 males and 2 females, mean age 66.9±9.2 years) a pleural effusion was detected and sampled. In 7 out of the 10 cases, the cytological examination of the fluid obtained by EUS-FNA tested positive for malignant cells, thereby upgrading the case to Stage IV, irrespective of T and N statuses. In 3 cases the cytology on the EUS-FNA material was proven to be negative for malignancy thereby allowing patients to be treated with curative intent without further delay.

CONCLUSIONS

EUS-FNA of the pleural fluid is a safe and simple procedure. Our data, albeit stemming from a limited study population, show that it can be efficient in selected NSCLC cases for obtaining useful material and information with significant impact on the staging and, therefore, on the planning of the optimum therapeutic strategy.