Frequency and characteristics of pleural effusions in pulmonary embolism.

Pulmonary embolism (PE) is the fourth cause of pleural effusions, after pneumonia, neoinfiltrates and tuberculosis. Several questions are yet unanswered: are the pleural effusions in PE exudates or transudates, what is their size, are they unilateral or bilateral, are they only haemorrhagic, etc. The aim of this study is to determine the frequency, side, size, biochemical and cytological characteristics of pleural effusions in PE.