Pleural effusion: diagnostic approach

Diagnosing pleural effusion (PE) can be complex and challenging. Due to the wide variety of possible clinical settings, proper management of pleural diseases should be tailored on a case-by-case basis and requires a multimodal approach. We provide an overview of the typical diagnostic approach. It is through a history, clinical assessment, evaluation of pretest probabilities, and careful selection of diagnostic tests, of which there are many, that a physician can be confident in their diagnosis. Radiological investigation of PE is key in diagnosing and determining management. Computed tomography is the modality of choice for the assessment of pleural disease. Thoracic ultrasound adds significant value in the identification of pleural fluid and pleural nodularity, guiding pleural procedures, and increasingly yielding diagnostic of pleural biopsy. Pleural biopsies are often necessary if a PE remains undiagnosed after radiological imaging and pleural fluid analysis. Thoracoscopic biopsies are the gold standard for investigating pleural disease. However, this service is not universally available and may be unsuitable for some patients. Image-guided biopsies are very useful in a wide patient population and have high diagnostic rates.