Current controversies in the management of malignant pleural effusions

Malignant pleural effusion (MPE) can complicate most malignancies and is a common clinical problem presenting to respiratory and cancer care physicians. Despite its frequent occurrence, current knowledge of MPE remains limited and controversy surrounds almost every aspect in its diagnosis and management. A lack of robust data has led to significant practice variations worldwide, inefficiencies in healthcare provision, and threats to patient safety. Recent studies have highlighted evolving concepts in MPE care that challenge traditional beliefs. Advancing laboratory techniques have improved the diagnostic yield from pleural fluid cytology, minimizing the need for invasive tissue biopsies, even in many cases of mesothelioma. Imaging-guided biopsy is comparable to thoracoscopy in suitable patients, if cytological examination was noncontributory. Cumulating evidence for the benefits of indwelling pleural catheters (IPCs) has led some centers to adopt this approach as first-line definitive management for MPE over conventional talc pleurodesis. The optimal technique of talc pleurodesis is still debated despite its use for many decades. Strategies combining pleurodesis and IPC are being studied. MPE consists of a heterogenous group of diseases and careful phenotyping of malignant effusion patients can provide important clinical information that will advance the field and allow better stratification of patients and planning of therapy accordingly. This review addresses the controversies in MPE diagnosis and management and exposes the deficits in knowledge of MPE that should be the focus of future research.