A pleural effusion of multiple causes

Multiple medical disorders can lead to the development of pleural effusions. Most effusions are given a single diagnosis in clinical practice. However, the cause of the effusion can change during the disease course, and concomitant yet distinct causes are often underrecognized. We highlight this point by reporting a complex case of recurrent pleural effusions with different predominant causes during the disease course. Five causes for the pleural effusion were diagnosed, namely malignant pleural effusion, empyema, chylothorax, transudative pleural effusion secondary to hypoalbuminemia, and esophagopleural fistula. This case serves as a reminder to clinicians that recurrent pleural effusion, even within the same pleural space, can arise from different causes and, whenever clinically appropriate, reinvestigation of the pleural effusion may be needed.