Diagnosis and Management of Pleural Transudates.

Various clinical trials have been published on the optimal clinical management of patients with pleural exudates, particularly those caused by malignant tumors, while little information is available on the diagnosis and treatment of pleural transudates. The etiology of pleural transudates is wide and heterogeneous, and they can be caused by rare diseases, sometimes constituting a diagnostic challenge. Analysis of the pleural fluid can be a useful procedure for establishing diagnosis. Treatment should target not only the underlying disease, but also management of the pleural effusion itself. In cases refractory to medical treatment, invasive procedures will be necessary, for example therapeutic thoracentesis, pleurodesis with talc, or insertion of an indwelling pleural catheter. Little evidence is currently available and no firm recommendations have been made to establish when to perform an invasive procedure, or to determine the safest, most efficient approach in each case. This article aims to describe the spectrum of diseases that cause pleural transudate, to review the diagnostic contribution of pleural fluid analysis, and to highlight the lack of evidence on the efficacy of invasive procedures in the management and control of pleural effusion in these patients.