Eosinophilic pleural effusions.

We present 2 cases of eosinophilic pleural effusion (EPE) seen recently at Straub Hospital. One occurred in a patient with pneumococcal empyema; the 2nd patient had 2 episodes of EPE secondary to malignant histiocytic lymphoma. Eosinophilic pleural effusion (EPE) is defined as having eosinophils exceeding 10% of the pleural fluid WBC differential. EPE is usually exudative, typically accounting for 1% to 8% of all pleural effusions. Up to 30% to 35% of EPE are idiopathic, while other frequent causes include air in the pleural space (30%), and pulmonary infections (10%). Collagen vascular diseases, tuberculosis and malignancies are common causes of EPE. Although spontaneous resolution and a favorable prognosis predominates in this entity, prudent clinical follow-up is advised. Since the first documented case of eosinophilic pleural effusion in 1984 by Harmsen, clinicians have attempted to determine its significance. This condition is defined as pleural effusion with greater than 10% of the WBC differential eosinophils. We saw 2 cases of EPE at Straub Hospital during 1988.