BackgroundPleural 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.ObjectiveThe 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 sourcesA 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 extractionFor 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.SynthesisThirty-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%).ConclusionsPleural 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.

Tissue processing is the technique by which fixed tissues are made suitable for embedding within a supportive medium such as paraffin, and consists of three sequential steps: dehydration, clearing, and infiltration. In most clinical and research settings, tissue processing is accomplished using an automated tissue processor, with or without microwave-assistance. To ensure high-quality results, processing protocols should be tailored to tissue size and composition by modifying variables such as reagents used and the timing of the various steps. Herein, we provide an overview of tissue processing theory and outline a basic tissue processing method for use with a conventional automated fluid transfer/enclosed processor. The principles described will assist readers in optimizing tissue processing for their own projects.

Browne et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 3.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Background: Suction and capillary pull are 2 biopsy techniques used in endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Although these techniques have been shown to perform comparably in terms of overall diagnostic yield, we hypothesized that the capillary pull technique would be associated with improved rapid on-site evaluation (ROSE) adequacy rates thus allowing for a shorter procedure time. Methods: One hundred eighteen patients undergoing EBUS-TBNA for any indication were randomized to suction or capillary pull techniques for the first biopsy pass; the technique used for all subsequent passes was based on operator preference and was not recorded. The first pass was subjected to ROSE and an adequacy assessment was given. ROSE slides were also scored for cellularity of diagnostic/lesional cells and blood contamination. The overall procedure time was also recorded. Results: There were no significant differences between suction and capillary pull techniques in terms of ROSE adequacy rates. Cellularity of diagnostic/lesional cells and blood contamination scores were also comparable. There was no significant difference in procedure time for the 2 techniques. Conclusion: This study suggests no differences in ROSE outcomes between suction and capillary pull techniques in EBUS-TBNA. The technique used should therefore be left to the discretion of the operator.