Pleural Fluid Cytology Yields and Time to Sample Processing

Area of Science:

• Cytopathology
• Thoracic Medicine
• Oncology Diagnostics

Background:

• Pleural fluid cytology is crucial for diagnosing malignant pleural effusions.
• Optimizing the timing of cytologic evaluation is key to maximizing diagnostic yield.
• This study investigates the impact of pre-analytical time on pleural fluid cytology effectiveness.

Purpose of the Study:

• To assess the diagnostic yield of pleural fluid cytology in relation to the time elapsed between sample collection and laboratory processing.
• To determine if delays in processing affect the detection of malignant cells in pleural effusions.

Main Methods:

• Retrospective analysis of 327 thoracentesis-derived pleural fluid samples.
• Samples processed using Diff-Quik®, ThinPrep®, and cell block techniques.
• Logistic regression and log-risk models analyzed the association between time to processing and malignant diagnosis.

Main Results:

• No statistically significant difference in diagnostic yield was observed based on the time between sample collection and processing.
• The time of day or day of the week of sample collection did not correlate with diagnostic yield.
• Results remained consistent even after adjusting for sample volume.

Conclusions:

• The study did not find a significant association between delayed processing and reduced cytology yield for malignant cells.
• Clinicians can be reassured that the timing of diagnostic thoracentesis likely does not influence the probability of a malignant diagnosis.
• Further research into sample processing and storage conditions is recommended to enhance diagnostic yield.